# GEVIBench > Open benchmark of 73 genetically encoded voltage indicators (GEVIs): published performance values curated from the original papers, normalized to one definition per metric, each linked to its source. Measured values only — no scores or rankings. Interpretation notes: - Brightness (B/B_EGFP): Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. - Kinetics τ_on / τ_off (ms): Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. - ΔF/F per 100 mV: Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. - ΔF/F per mV: Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. - ΔF/F per AP: Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. - AP width (FWHM, ms): Full width at half maximum of the optical spike waveform. - Photostability t75% @ 100 mW/mm²: Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. - Papers using it (N_used): Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). - Brightness values are relative to EGFP (1.0 = as bright as EGFP). Opsin-based sensors are typically 10⁻³–10⁻² and are imaged at much higher illumination. - Values from different preparations (culture, slice, in vivo; 1P vs 2P) are listed separately on each sensor page with their source. Cite as: Adam E. Cohen and Daozheng Gong (2026). Voltage imaging: A practical guide. Neuron. https://doi.org/10.1016/j.neuron.2026.08.002 ## Summary of all 73 sensors | Sensor | Year | Category | Polarity | B/B_EGFP | τ_on / τ_off (ms) | ΔF/F per 100 mV | ΔF/F per mV | ΔF/F per AP | AP FWHM | t75% @100 mW/mm² | Papers | |---|---|---|---|---|---|---|---|---|---|---|---| | [2Photron](https://gevibench.org/gevi/2photron) | 2024 | Chemigenetic GEVI | negative | 2.42× | 1.6 / 2.2 | -24% | 0.28% | 5.72% | 1.4 ms | — | 1 | | [Ace2N-mNeon](https://gevibench.org/gevi/ace2n-mneon) | 2015 | eFRET GEVI | negative | 2.73× | 2.2 / 3.8 | -17.9% | 0.091% | 5% | 3.9 ms | 11 s | 6 | | [Ace2N-mNeon2](https://gevibench.org/gevi/ace2n-mneon2) | 2022 | eFRET GEVI | negative | 3.04× | 1.5 / 1.5 | -26.1% | 0.2% | 16.5% | 5 ms | 17 s | 5 | | [AMBER](https://gevibench.org/gevi/amber) | 2021 | Bioluminescent GEVI | positive | — | 40 / 30 | +200% | — | — | — | bioluminescent (no photobleaching) | 1 | | [Arch](https://gevibench.org/gevi/arch) | 2012 | Opsin GEVI | positive | 0.00030× | 0.50 / 0.50 | +45% | 0.17% | — | 4.3 ms | — | 10 | | [Archer1](https://gevibench.org/gevi/archer1) | 2014 | Opsin GEVI | positive | 0.0011× | 2.5 / 5.5 | +85% | 0.78% | 33% | — | 55.0 min | 6 | | [Archer2](https://gevibench.org/gevi/archer2) | 2014 | Opsin GEVI | positive | 0.0016× | — | +60% | 0.45% | — | — | — | 3 | | [Archon1](https://gevibench.org/gevi/archon1) | 2018 | Opsin GEVI | positive | 0.0039× | 1.5 / 2.5 | +43% | 0.4% | 30% | 2.6 ms | 7.0 h | 16 | | [Archon2](https://gevibench.org/gevi/archon2) | 2018 | Opsin GEVI | positive | 0.0067× | 2.0 / 0.72 | +20% | 0.2% | 18% | 2.4 ms | 1.2 h | 4 | | [ArcLight](https://gevibench.org/gevi/arclight) | 2012 | VSD-single FP | negative | 0.66× | 25 / 30 | -35% | 0.47% | 3.2% | 6.6 ms | 7.3 s | 53 | | [ASAP1](https://gevibench.org/gevi/asap1) | 2014 | VSD-cpGFP GEVI | negative | 0.43× | 6.7 / 12 | -17.5% | 0.21% | 6.3% | 6.2 ms | 11 s | 21 | | [ASAP2s](https://gevibench.org/gevi/asap2s) | 2017 | VSD-cpGFP GEVI | negative | 0.43× | 7.8 / 14 | -38.7% | 0.15% | 12.2% | 15 ms | 5.5 s | 13 | | [ASAP3](https://gevibench.org/gevi/asap3) | 2019 | VSD-cpGFP GEVI | negative | 0.45× | 6.8 / 11 | -51% | 0.68% | 18% | 5.7 ms | 52 s | 27 | | [ASAP4b](https://gevibench.org/gevi/asap4b) | 2023 | VSD-cpGFP GEVI | positive | 0.20× | 5.6 / 7.0 | +180% | 1.3% | 35% | 8.7 ms | 59 s | 5 | | [ASAP4e](https://gevibench.org/gevi/asap4e) | 2023 | VSD-cpGFP GEVI | positive | 0.17× | 6.3 / 5.7 | +210% | 1.1% | 38% | 5 ms | — | 6 | | [ASAP5](https://gevibench.org/gevi/asap5) | 2024 | VSD-cpGFP GEVI | negative | 0.31× | 3.0 / 2.6 | -57% | 1.3% | 34% | 4 ms | 17 s | 11 | | [ASAP6c](https://gevibench.org/gevi/asap6c) | 2026 | VSD-cpGFP GEVI | positive | 0.11× | 3.9 / 4.4 | +222% | 1.1% | 70% | 5.3 ms | — | 1 | | [ASAP7y](https://gevibench.org/gevi/asap7y) | 2026 | VSD-cpGFP GEVI | negative | 0.34× | 0.90 / 2.7 | -80% | 2% | 62% | 10 ms | 1.3 s | 3 | | [Bongwoori](https://gevibench.org/gevi/bongwoori) | 2015 | VSD-single FP | negative | 0.19× | 14 / 11 | -13% | 0.05% | 3.7% | 33 ms | 1.2 s | 9 | | [Bongwoori-R3](https://gevibench.org/gevi/bongwoori-r3) | 2017 | VSD-single FP | negative | 0.36× | 11 / 10 | -20% | 0.1% | 5.9% | — | 3.0 s | 4 | | [CAESR](https://gevibench.org/gevi/caesr) | 2014 | eFRET GEVI | negative | 1.43× | 9.9 / 15 | -13.1% | 0.14% | 9.7% | — | — | 2 | | [Cepheid1b](https://gevibench.org/gevi/cepheid1b) | 2023 | eFRET GEVI | negative | 1.40× | 2.7 / 5.0 | -31% | 0.4% | 12.1% | 7 ms | 17 s | 2 | | [Cepheid1s](https://gevibench.org/gevi/cepheid1s) | 2023 | eFRET GEVI | negative | 0.36× | 2.0 / 3.5 | -30% | 0.4% | 13.3% | 7.9 ms | — | 2 | | [ElectraOFF](https://gevibench.org/gevi/electraoff) | 2025 | eFRET GEVI | negative | 4.86× | 1.8 / 1.1 | -13% | 0.1% | 14.5% | 6.4 ms | 1.1 min | 2 | | [ElectraON](https://gevibench.org/gevi/electraon) | 2025 | eFRET GEVI | positive | 2.51× | 1.1 / 0.58 | +10% | 0.1% | 22.8% | 4.8 ms | — | 1 | | [ElectricPk](https://gevibench.org/gevi/electricpk) | 2012 | VSD-cpGFP GEVI | negative | 0.32× | 2.2 / 36 | -1.2% | 0.02% | 0.7% | 4.4 ms | — | 1 | | [FlicR1](https://gevibench.org/gevi/flicr1) | 2016 | VSD-single FP | positive | 0.34× | 3.4 / 3.7 | +6.6% | 0.067% | 2.6% | 6.8 ms | 48 s | 5 | | [FlicR2](https://gevibench.org/gevi/flicr2) | 2018 | VSD-single FP | positive | 0.50× | 16 / 16 | +12.9% | 0.14% | — | — | — | 2 | | [FORCE1s](https://gevibench.org/gevi/forces1) | 2026 | VSD-cpGFP GEVI | positive | 0.22× | 3.7 / 6.0 | +267% | 1.2% | 92.7% | 3.8 ms | — | 1 | | [HArclight1](https://gevibench.org/gevi/harclight1) | 2021 | Chemigenetic GEVI | negative | 1.81× | 5.1 / 5.7 | -3.5% | 0.05% | — | — | — | 1 | | [HASAP1](https://gevibench.org/gevi/hasap1) | 2021 | Chemigenetic GEVI | positive | 1.81× | 2.2 / 2.4 | +9.3% | 0.075% | 3.7% | 15 ms | — | 1 | | [HVI](https://gevibench.org/gevi/hvi) | 2021 | Chemigenetic GEVI | negative | 2.10× | 1.7 / 2.5 | -39.1% | 0.28% | 25.3% | 12 ms | 1.2 min | 3 | | [HVI+](https://gevibench.org/gevi/hviplus) | 2025 | Chemigenetic GEVI | positive | 1.11× | 6.8 / 5.5 | +55% | 0.22% | 22.3% | 9.5 ms | 3.2 min | 1 | | [Jarvis](https://gevibench.org/gevi/jarvis) | 2026 | eFRET GEVI | positive | 1.39× | 2.7 / 1.9 | +29% | 0.2% | 25% | 1.7 ms | 2.1 min | 1 | | [JEDI-1P](https://gevibench.org/gevi/jedi1p) | 2023 | VSD-cpGFP GEVI | negative | 0.89× | 5.1 / 6.2 | -56% | 0.9% | 31.2% | 4.9 ms | 54 s | 7 | | [JEDI-2P](https://gevibench.org/gevi/jedi2p) | 2022 | VSD-cpGFP GEVI | negative | 0.51× | 2.1 / 2.8 | -48% | 0.7% | 18.2% | 1.6 ms | 14 s | 14 | | [JEDI-3hyp](https://gevibench.org/gevi/jedi3hyp) | 2026 | VSD-cpGFP GEVI | negative | 0.41× | 1.2 / 2.1 | -51.5% | 1.9% | 36.4% | 3.8 ms | — | 1 | | [JEDI-3sub](https://gevibench.org/gevi/jedi3sub) | 2026 | VSD-cpGFP GEVI | negative | 0.46× | 1.1 / 2.2 | -63.5% | 1.3% | 42.8% | 3.9 ms | — | 1 | | [LOTUS-V](https://gevibench.org/gevi/lotusv) | 2017 | Bioluminescent GEVI | positive | — | 129 / 103 | +21% | 0.14% | 2.8% | 11 ms | bioluminescent (no photobleaching) | 2 | | [MacQ-mCitrine](https://gevibench.org/gevi/macq-mcitrine) | 2014 | eFRET GEVI | negative | 1.96× | 21 / 20 | -20% | 0.2% | 4.8% | 10 ms | 2.6 s | 5 | | [MacQ-mOrange2](https://gevibench.org/gevi/macq-morange2) | 2014 | eFRET GEVI | negative | 1.96× | 7.4 / 6.9 | -20% | 0.25% | 7.2% | — | 6.5 s | 1 | | [Marina](https://gevibench.org/gevi/marina) | 2017 | VSD-single FP | positive | 0.44× | 29 / 33 | +29% | 0.25% | 1.4% | — | 49 s | 4 | | [Mermaid](https://gevibench.org/gevi/mermaid) | 2008 | VSD-FRET GEVI | positive | 1.29× | 10 / 19 | +40% | 0.25% | 1.6% | — | 4.1 s | 9 | | [Mermaid2](https://gevibench.org/gevi/mermaid2) | 2013 | VSD-FRET GEVI | positive | — | 3.5 / 10 | +48.5% | 0.35% | 2.57% | — | — | 1 | | [nirButterfly](https://gevibench.org/gevi/nirbutterfly) | 2020 | VSD-FRET GEVI | negative | 0.04× | 2.2 / 2.1 | -9.8% | 0.1% | -6% | — | 1.0 min | 2 | | [NovArch](https://gevibench.org/gevi/novarch) | 2021 | Opsin GEVI | positive | 0.01× | 3.3 / 5.7 | +41% | 0.41% | 28% | 5.9 ms | 33.6 min | 2 | | [pAce](https://gevibench.org/gevi/pace) | 2022 | eFRET GEVI | positive | 2.40× | 0.69 / 1.2 | +30.5% | 0.33% | 10.7% | 4.3 ms | 32 s | 7 | | [pAceR](https://gevibench.org/gevi/pacer) | 2022 | eFRET GEVI | positive | 0.59× | 3.8 / 4.1 | +27.8% | 0.2% | 3.2% | 2.7 ms | 41 s | 2 | | [Pado](https://gevibench.org/gevi/pado) | 2016 | VSD-single FP | negative | — | 93 / 10 | -5% | 0.05% | — | — | — | 1 | | [paQuasAr3](https://gevibench.org/gevi/quasar3) | 2019 | Opsin GEVI | positive | 0.0012× | 8.1 / 4.7 | +40% | 0.4% | 23.5% | 1.8 ms | 3.3 h | 12 | | [Positron](https://gevibench.org/gevi/positron) | 2020 | Chemigenetic GEVI | positive | 1.56× | 3.4 / 4.3 | +23% | 0.25% | 5.9% | — | 48 s | 3 | | [Positron2](https://gevibench.org/gevi/positron2) | 2022 | Chemigenetic GEVI | positive | — | — | +37% | 0.38% | 15% | — | — | 1 | | [PROPS](https://gevibench.org/gevi/props) | 2011 | Opsin GEVI | positive | — | 4.7 / 4.7 | +150% | 0.8% | — | — | — | 4 | | [QuasAr1](https://gevibench.org/gevi/quasar1) | 2014 | Opsin GEVI | positive | 0.0028× | 0.24 / 0.29 | +32% | 0.25% | 21% | 2.6 ms | — | 1 | | [QuasAr2](https://gevibench.org/gevi/quasar2) | 2014 | Opsin GEVI | positive | 0.00086× | 1.1 / 1.5 | +90% | 0.7% | 48% | 4.5 ms | 3.1 h | 23 | | [QuasAr6a](https://gevibench.org/gevi/quasar6) | 2023 | Opsin GEVI | positive | 0.0066× | 2.3 / 1.6 | +73% | 0.7% | 23% | 2.4 ms | 5.2 h | 5 | | [QuasAr6b](https://gevibench.org/gevi/quasar6b) | 2023 | Opsin GEVI | positive | 0.0078× | 1.6 / 1.5 | +24% | 0.2% | 14% | 1.6 ms | 4.7 h | 2 | | [rEstus](https://gevibench.org/gevi/restus) | 2024 | VSD-cpGFP GEVI | negative | 0.85× | 14 / 51 | -62% | 1.3% | — | — | — | 5 | | [rEstus-NI](https://gevibench.org/gevi/restus-ni) | 2025 | VSD-cpGFP GEVI | negative | 0.84× | 181 / 433 | -57% | 1.1% | — | — | — | 1 | | [rEstus2s](https://gevibench.org/gevi/restus2s) | 2026 | VSD-cpGFP GEVI | negative | 0.56× | 12 / 42 | -83% | 1.6% | — | — | — | 1 | | [Solaris](https://gevibench.org/gevi/solaris) | 2024 | Chemigenetic GEVI | negative | — | 2.5 / 2.5 | -53% | 1% | -28.1% | 12 ms | — | 1 | | [SomArchon](https://gevibench.org/gevi/somarchon) | 2019 | Opsin GEVI | positive | 0.01× | 0.60 / 1.1 | +30% | 0.35% | 43% | 4.7 ms | 49.0 min | 16 | | [VADER1](https://gevibench.org/gevi/vader1) | 2026 | VSD-single FP | positive | 0.42× | 1.4 / 5.2 | +42% | 0.067% | 40% | 3.6 ms | — | 1 | | [VARNAM](https://gevibench.org/gevi/varnam) | 2018 | eFRET GEVI | negative | 0.85× | 3.0 / 2.8 | -10.8% | 0.1% | 4.8% | 3.6 ms | 30 s | 7 | | [VARNAM2](https://gevibench.org/gevi/varnam2) | 2022 | eFRET GEVI | negative | 0.85× | 0.95 / 1.2 | -19.1% | 0.23% | 7.3% | 5.3 ms | 1.7 min | 3 | | [Vega](https://gevibench.org/gevi/vega) | 2025 | eFRET GEVI | negative | 6.80× | 1.3 / 3.7 | -33.1% | 0.5% | 17.1% | 4.8 ms | 4.7 min | 1 | | [Voltron](https://gevibench.org/gevi/voltron) | 2019 | Chemigenetic GEVI | negative | 11.04× | 2.0 / 2.2 | -23% | 0.21% | 6.16% | 3 ms | 25 s | 9 | | [Voltron2](https://gevibench.org/gevi/voltron2) | 2023 | Chemigenetic GEVI | negative | 7.18× | 4.0 / 5.5 | -34% | 0.51% | 10.09% | 3.2 ms | 42 s | 23 | | [VSFP-Butterfly](https://gevibench.org/gevi/vsfpbutterfly) | 2012 | VSD-FRET GEVI | positive | 1.74× | 7.7 / 90 | +6% | 0.042% | 0.3% | — | — | 28 | | [VSFP1](https://gevibench.org/gevi/vsfp1) | 2001 | VSD-FRET GEVI | positive | — | 0.74 / 0.74 | +1.8% | 0.018% | — | — | — | 1 | | [VSFP2.1](https://gevibench.org/gevi/vsfp2) | 2007 | VSD-FRET GEVI | positive | — | 15 / 75 | +2.7% | 0.086% | — | — | — | 2 | | [VSFP2.3](https://gevibench.org/gevi/vsfp2_3) | 2008 | VSD-FRET GEVI | positive | 1.74× | 49 / 70 | -8.3% | 0.15% | 0.2% | — | — | 8 | | [VSFP3.1](https://gevibench.org/gevi/vsfp3_1) | 2009 | VSD-FRET GEVI | negative | 0.79× | 25 / NaN | -1.3% | 0.02% | 0.075% | — | — | 5 | ## 2Photron Chemigenetic voltage indicator built from Klebsormidium nitens rhodopsin and HaloTag, engineered for two-photon voltage imaging. - Category: Chemigenetic GEVI - Published: 2024-11-17 — [bioRxiv 2024](https://doi.org/10.1101/2024.11.15.623698) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 560 nm, emission peak 581 nm (2Photron (JF552)) - Two-photon compatible: yes - Tags: Klebsormidium rhodopsin, HaloTag, Two-photon, Red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 2.42× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.6 / 2.2 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -24% (median of 2 measurements: −24%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.28% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 5.72% (median of 2 measurements: 6.8%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 1.4 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.64 ms, τ_off 2.21 ms at 25°C — [Villette 2024, Fig. S6](https://doi.org/10.1101/2024.11.15.623698) #### ΔF/F per 100 mV - -24%, 1P, dye JF552 — [Villette 2024, Fig. 2B](https://doi.org/10.1101/2024.11.15.623698) - -24.5%, 2P, dye JF552 — [Villette 2024, Fig. 2B](https://doi.org/10.1101/2024.11.15.623698) #### ΔF/F per action potential - 5.72%, 2P, dye JF552 — [Villette 2024, Fig. 3f](https://doi.org/10.1101/2024.11.15.623698) - 7.88%, 2P, dye JF552 — [Villette 2024, Fig. S9](https://doi.org/10.1101/2024.11.15.623698) #### AP width (FWHM) - 1.42 ms at 3500 Hz sampling, Mouse, V1 cortex layer II/III, awake behaving, in vivo (soma-targeted 2Photron-ST552), 2P, 37°C — [Villette 2024, Fig. 3f](https://doi.org/10.1101/2024.11.15.623698) #### Brightness comparisons - 4.12× the brightness of JEDI-2P — [Villette 2024, Fig. 3f](https://doi.org/10.1101/2024.11.15.623698) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -145 mV: 18%; -120 mV: 13%; -95 mV: 7%; -70 mV: 0%; -45 mV: -7%; -20 mV: -14%; 5 mV: -19%; 30 mV: -24%; 55 mV: -28% — [Villette 2024, Fig. 2B](https://doi.org/10.1101/2024.11.15.623698) ### Research papers using 2Photron (1) - [A novel rhodopsin-based voltage indicator for simultaneous two-photon optical recording with GCaMP in vivo](https://doi.org/10.1101/2024.11.15.623698) — Villette V, et al., bioRxiv 2024 (Mouse, visual cortex, in vivo, two-photon; mouse, cerebellum Golgi cells, in vivo, two-photon; rat, hippocampal neurons, in vitro) ## Ace2N-mNeon Opsin-fluorescent protein FRET voltage indicator pairing an Ace rhodopsin with mNeonGreen, optimized for fast sub-millisecond responses and high-fidelity spike detection. - Category: eFRET GEVI - Published: 2015-12-11 — [Science 2015](https://doi.org/10.1126/science.aab0810) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 506 nm, emission peak 517 nm (Ace2N-mNeon) - Two-photon compatible: no - Tags: Ace opsin ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 2.73× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.2 / 3.8 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -17.9% (median of 6 measurements: −11.6%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.091% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 5% (median of 4 measurements: 4.95%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 3.9 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 11 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 6 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.36 ms, τ_off 2.14 ms at 22°C — [Gong 2015, Table S2](https://doi.org/10.1126/science.aab0810) - τ_on 2.2 ms, τ_off 3.8 ms at 33-34°C — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - τ_on 2.33 ms, τ_off 2.54 ms at 22°C — [Kannan 2018, Table S1](https://doi.org/10.1038/s41592-018-0188-7) #### ΔF/F per 100 mV - -17.9% (peak), 1P — [Gong 2015, Fig. 1D](https://doi.org/10.1126/science.aab0810) - -5%, 1P — [Gong 2015, Fig. 1D](https://doi.org/10.1126/science.aab0810) - -19.4% (peak), 1P — [Gong 2015, Fig. S6C](https://doi.org/10.1126/science.aab0810) - -9%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - -11.6%, 1P — [Kannan 2018, Fig. 2b](https://doi.org/10.1038/s41592-018-0188-7) - -11.5%, 1P — [Hasseman 2022, Fig. 1](https://doi.org/10.25378/janelia.21534411) #### ΔF/F per mV (subthreshold) - 0.091%/mV — [Abdelfattah 2023, Fig. S5D](https://doi.org/10.1016/j.neuron.2023.03.009) #### ΔF/F per action potential - 5%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 5%, 1P — [Hasseman 2022, Fig. 2](https://doi.org/10.25378/janelia.21534411) - 4.9%, 1P — [Liu 2021, Table S3](https://doi.org/10.1038/s41557-021-00641-1) - 4.3%, 1P — [Kannan 2018, Fig. 3d](https://doi.org/10.1038/s41592-018-0188-7) #### AP width (FWHM) - 3.9 ms at 500 Hz sampling, Drosophila, PPL1-α'2α2 dopaminergic neuron, in vivo, 1P, 25°C — [Kannan 2018, Fig. S15](https://doi.org/10.1038/s41592-018-0188-7) #### Brightness comparisons - 2.76× the brightness of EGFP — [Shaner 2013, Table 1](https://doi.org/10.1038/nmeth.2413) - 0.9090909090909091× the brightness of Ace2N-mNeon2 — [Kannan 2022, Fig. S11A](https://doi.org/10.1126/science.abm8797) - 5.988023952095808× the brightness of ASAP3 — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 5.555555555555555× the brightness of FlicR1 — [Kannan 2018, Fig. 1j](https://doi.org/10.1038/s41592-018-0188-7) - 5.555555555555555× the brightness of FlicR2 — [Kannan 2018, Fig. 1j](https://doi.org/10.1038/s41592-018-0188-7) - 1.4285714285714286× the brightness of pAce — [Kannan 2022, Fig. S11A](https://doi.org/10.1126/science.abm8797) - 1.4084507042253522× the brightness of VARNAM — [Kannan 2018, Fig. 1j](https://doi.org/10.1038/s41592-018-0188-7) - 0.25× the brightness of Voltron — [Abdelfattah 2019, Fig. 1F](https://doi.org/10.1126/science.aav6416) #### Photobleaching - t75% = 92 s, 1P — [Kannan 2022, Fig. S11B](https://doi.org/10.1126/science.abm8797) - t75% = 49 s at 31 mW/mm², 1P — [Liu 2021, Ext. Fig. 4g](https://doi.org/10.1038/s41557-021-00641-1) - t75% = 32 s at ~23 mW/mm² (475/50 nm), 1P — [Abdelfattah 2019, Fig. 1H](https://doi.org/10.1126/science.aav6416) - t75% = 31 s at 15 mW/mm², 1P — [Kannan 2018, Fig. S7a](https://doi.org/10.1038/s41592-018-0188-7) - t75% = 104 s at 13 mW/mm², 1P — [Piatkevich 2018, Fig. 2i](https://doi.org/10.1038/s41589-018-0004-9) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 5.4%; -70 mV: 0%; -50 mV: -3.6%; -30 mV: -7.2%; 0 mV: -12.6%; 30 mV: -17.9% — [Gong 2015, Fig. 1D](https://doi.org/10.1126/science.aab0810) ### Research papers using Ace2N-mNeon (6) - [High-speed recording of neural spikes in awake mice and flies with a fluorescent voltage sensor](https://doi.org/10.1126/science.aab0810) — Gong Y, et al., Science 2015 (Rat hippocampal neurons, in vitro; mouse V1 cortex, in vivo; Drosophila olfactory neurons, in vivo) - [Long-term optical brain imaging in live adult fruit flies](https://doi.org/10.1038/s41467-018-02873-1) — Huang C, et al., Nature Communications 2018 (Drosophila, dopamine neurons, in vivo) - [Comparative Evaluation of Genetically Encoded Voltage Indicators](https://doi.org/10.1016/j.celrep.2018.12.088) — Bando Y, et al., Cell Reports 2019 (Mouse hippocampal neurons, in vitro; mouse visual cortex, in vivo) - [Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators](https://doi.org/10.7554/eLife.25690) — Chamberland S, et al., eLife 2017 (Drosophila visual neurons (L2), in vivo; rat hippocampal organotypic slices, in vitro) - [Exploring Bioelectricity with Ace2N-mNeon during Zebrafish Embryogenesis](https://doi.org/10.1101/2024.12.12.628143) — Wu Z, et al., bioRxiv 2024 (Zebrafish embryos, neurons and cardiomyocytes, in vivo) - [Imaging high-frequency voltage dynamics in multiple neuron classes of behaving mammals](https://doi.org/10.1016/j.cell.2025.06.028) — Haziza S, et al., Cell 2025 (Mouse, cortex, in vivo) ## Ace2N-mNeon2 Improved Ace2N-mNeon variant optimized for lower illumination power. - Category: eFRET GEVI - Published: 2022-11-04 — [Science 2022](https://doi.org/10.1126/science.abm8797) - Derived from: [Ace2N-mNeon](https://gevibench.org/gevi/ace2n-mneon) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 506 nm, emission peak 517 nm (Ace2N-mNeon2) - Plasmid: [Addgene #195518](https://www.addgene.org/195518/) - Tags: Ace opsin ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 3.04× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.5 / 1.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -26.1% (median of 3 measurements: −26.7%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.2% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 16.5% (median of 3 measurements: 13.2%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 5 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 17 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 5 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.54 ms, τ_off 1.51 ms at 22°C — [Kannan 2022, Table S1](https://doi.org/10.1126/science.abm8797) #### ΔF/F per 100 mV - -26.1%, 1P — [Kannan 2022, Table S1](https://doi.org/10.1126/science.abm8797) - -26.7%, 1P — [Cao 2025, Table S2](https://doi.org/10.1101/2025.05.29.656768) - -29.5%, 1P — [Hasseman 2022, Fig. 1](https://doi.org/10.25378/janelia.21534411) #### ΔF/F per action potential - 16.5%, 1P — [Kannan 2022, Fig. 1I](https://doi.org/10.1126/science.abm8797) - 11%, 1P — [Hasseman 2022, Fig. 2](https://doi.org/10.25378/janelia.21534411) - 13.2%, 1P — [Cao 2025, Table S2](https://doi.org/10.1101/2025.05.29.656768) #### AP width (FWHM) - 2.1 ms at 400 Hz sampling, Mouse, V1 VIP+ interneurons, awake, in vivo, 1P, 37°C — [Kannan 2022, Fig. 1I](https://doi.org/10.1126/science.abm8797) - 8 ms at 1000 Hz sampling, Mouse, primary hippocampal neurons, in vitro (culture), 1P, 22°C — [Zhang 2025, Fig. 1j](https://doi.org/10.1101/2025.05.30.657123) #### Brightness comparisons - 1.1× the brightness of Ace2N-mNeon — [Kannan 2022, Fig. S11A](https://doi.org/10.1126/science.abm8797) - 0.5× the brightness of Vega — [Cao 2025, Fig. 1B](https://doi.org/10.1101/2025.05.29.656768) - 0.625× the brightness of ElectraOFF — [Zhang 2025, Fig. 1e](https://doi.org/10.1101/2025.05.30.657123) #### Photobleaching - t75% = 277 s at 5 mW/mm², 1P — [Zhang 2025, Fig. S4h](https://doi.org/10.1101/2025.05.30.657123) - t75% = 35 s at 30 mW/mm², 1P — [Cao 2025, Fig. 1D](https://doi.org/10.1101/2025.05.29.656768) - t75% = 79 s, 1P — [Kannan 2022, Fig. S11B](https://doi.org/10.1126/science.abm8797) - t75% = 332 s at 10 mW/mm², 1P — [Zhang 2025, Fig. 1h](https://doi.org/10.1101/2025.05.30.657123) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -150 mV: 15%; -130 mV: 12%; -110 mV: 8%; -90 mV: 4%; -70 mV: 0%; -50 mV: -4%; -30 mV: -10%; -10 mV: -15%; 10 mV: -21%; 30 mV: -25%; 50 mV: -31% — [Kannan 2022, Fig. 1D](https://doi.org/10.1126/science.abm8797) ### Research papers using Ace2N-mNeon2 (5) - [Dual-polarity voltage imaging of the concurrent dynamics of multiple neuron types](https://doi.org/10.1126/science.abm8797) — Kannan M, Vasan G, Haziza S, Huang C, Chrapkiewicz R, Luo J, Cardin JA, Schnitzer MJ, Pieribone VA, Science 2022 (Mouse, visual cortex and hippocampus, in vivo; Drosophila, dopamine neurons, in vivo; HEK cells, in vitro) - [Imaging high-frequency voltage dynamics in multiple neuron classes of behaving mammals](https://doi.org/10.1016/j.cell.2025.06.028) — Haziza S, et al., Cell 2025 (Mouse, visual cortex and hippocampus, in vivo) - [Prefrontal gamma oscillations engage dynamic cell type-specific configurations to support flexible behavior](https://doi.org/10.1101/2024.03.08.584173) — Phensy AJ, et al., bioRxiv 2025 (Mouse, medial prefrontal cortex, in vivo) - [Bright and Photostable Voltage Sensors Derived from mBaoJin](https://doi.org/10.1101/2025.05.30.657123) — Zhang H, Zhou S, Kuzmicheva TP, Subach OM, Grimm C, Eom M, Baror-Sebban S, Adam Y, Yoon YG, Emilliani V, Subach FV, Piatkevich KD, bioRxiv 2025 (HeLa cells; Mouse, primary hippocampal neurons, in vitro; Mouse, hippocampus CA1, in vivo (benchmark comparison against ElectraON/ElectraOFF)) - [A photostable genetically encoded voltage indicator for imaging neural activities in tissue and live animals](https://doi.org/10.1101/2025.05.29.656768) — Cao C, Zhu R, Zhou S, Zhao Z, Lin C, Liu S, Peng L, Subach FV, Piatkevich KD, Zou P, bioRxiv 2025 (HEK293T cells, in vitro; Rat, hippocampal neurons, in vitro; Mouse, acute brain slices, ex vivo) ## AMBER First autonomous bioluminescent voltage indicator by pairing a VSD with a self-sufficient luciferase enzyme. - Category: Bioluminescent GEVI - Published: 2021-11-10 — [Advanced Biology 2021](https://doi.org/10.1002/adbi.202100842) - Derived from: [VSFP2.1](https://gevibench.org/gevi/vsfp2) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 490 nm, emission peak 528 nm (AMBER) - Bioluminescent: emits light enzymatically, needs no excitation and does not photobleach - Tags: Luciferase, Bioluminescent, Positive-going, YPet, BRET ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 40 / 30 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +200% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | — | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | bioluminescent (no photobleaching) | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 40 ms, τ_off 30 ms at 25°C — [Srinivasan 2021, Fig. 3B](https://doi.org/10.1002/adbi.202100842) #### ΔF/F per 100 mV - +200% — [Srinivasan 2021, Fig. 2A](https://doi.org/10.1002/adbi.202100842) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -60 mV: 0%; -40 mV: 14%; -20 mV: 68%; 0 mV: 88%; 20 mV: 97%; 40 mV: 100%; 60 mV: 99% — [Srinivasan 2021, Fig. 2B](https://doi.org/10.1002/adbi.202100842) ### Research papers using AMBER (1) - [An Autonomous Molecular Bioluminescent Reporter (AMBER) for Voltage Imaging in Freely Moving Animals](https://doi.org/10.1002/adbi.202100842) — Srinivasan P, Griffin NM, Thakur DP, Joshi PM, Nguyen-Le A, McCotter S, Jain A, Saeidi M, Kulkarni P, Eisdorfer JT, Rothman JH, Montell C, Theogarajan L, Advanced Biology 2021 (C. elegans, pharyngeal muscle and mechanosensory neurons, in vivo) ## Arch The first archaerhodopsin-based voltage indicator, establishing that microbial opsins can optically report membrane potential, though with extremely dim baseline fluorescence. - Category: Opsin GEVI - Published: 2011-11-27 — [Nature Methods 2012](https://doi.org/10.1038/nmeth.1782) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 558 nm, emission peak 687 nm (Arch) - Tags: Archaerhodopsin, Red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.00030× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 0.50 / 0.50 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +45% (median of 2 measurements: +42.5%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.17% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4.3 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 10 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 0.5 ms, τ_off 0.5 ms at 24°C — [Kralj 2012, Fig. 1d](https://doi.org/10.1038/nmeth.1782) - τ_on 0.6 ms, τ_off 0.8 ms at 23°C — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) #### ΔF/F per 100 mV - +45%, 1P — [Kralj 2012, Fig. 1c](https://doi.org/10.1038/nmeth.1782) - +40%, 1P — [Hochbaum 2014, Fig. 1c](https://doi.org/10.1038/nmeth.3000) #### AP width (FWHM) - 4.3 ms at 2000 Hz sampling, Cultured rat hippocampal neurons, in vitro, 1P, 24°C — [Kralj 2012, Fig. 2f](https://doi.org/10.1038/nmeth.1782) #### Brightness comparisons - 0.00016× the brightness of EGFP — [Herasymenko 2025, Table 1](https://doi.org/10.1039/D4SC05120C) - 0.2× the brightness of Archer1 — [Flytzanis 2014, Fig. 1a](https://doi.org/10.1038/ncomms5894) - 0.3333333333333333× the brightness of Archer2 — [Flytzanis 2014, Fig. 1a](https://doi.org/10.1038/ncomms5894) - 0.0006858710562414266× the brightness of FlicR1 — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 0.00205761316872428× the brightness of nirButterfly — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 0.06578947368421052× the brightness of QuasAr1 — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) - 0.05× the brightness of QuasAr1 — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 0.29411764705882354× the brightness of QuasAr2 — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) - 0.03571428571428571× the brightness of SomArchon — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 0.0004374453193350831× the brightness of VARNAM — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -150 mV: -13%; -120 mV: -8%; -90 mV: -4%; -70 mV: 0%; -60 mV: 1%; -30 mV: 4%; 0 mV: 9%; 30 mV: 11%; 60 mV: 13%; 90 mV: 17%; 120 mV: 18%; 150 mV: 21% — [Maclaurin 2013, Fig. 2A](https://doi.org/10.1073/pnas.1215595110) ### Research papers using Arch (10) - [Optical recording of action potentials in mammalian neurons using a microbial rhodopsin](https://doi.org/10.1038/nmeth.1782) — Kralj JM, Douglass AD, Hochbaum DR, Maclaurin D, Cohen AE, Nature Methods 2012 (Cultured rat hippocampal neurons, HEK293 cells, in vitro) - [Mechanism of voltage-sensitive fluorescence in a microbial rhodopsin](https://doi.org/10.1073/pnas.1215595110) — Maclaurin D, Venkatachalam V, Lee H, Cohen AE, Proceedings of the National Academy of Sciences 2013 (HEK293 cells and cultured neurons, in vitro) - [Enhanced archaerhodopsin fluorescent protein voltage indicators](https://doi.org/10.1371/journal.pone.0066959) — Gong Y, Li JZ, Schnitzer MJ, PLoS One 2013 (Cultured rat hippocampal neurons, in vitro) - [Archaerhodopsin voltage imaging: synaptic calcium and BK channels stabilize action potential repolarization at the Drosophila neuromuscular junction](https://doi.org/10.1523/JNEUROSCI.2203-14.2014) — Ford KJ, Davis GW, Journal of Neuroscience 2014 (Drosophila neuromuscular junction, in vivo) - [Archaerhodopsin variants with enhanced voltage-sensitive fluorescence in mammalian and Caenorhabditis elegans neurons](https://doi.org/10.1038/ncomms5894) — Flytzanis NC, Bedbrook CN, Chiu H, Engqvist MKM, Xiao C, Chan KY, Sternberg PW, Arnold FH, Gradinaru V, Nature Communications 2014 (Cultured rat hippocampal neurons and C. elegans neurons, in vitro/in vivo) - [All-optical electrophysiology in mammalian neurons using engineered microbial rhodopsins](https://doi.org/10.1038/nmeth.3000) — Hochbaum DR, Zhao Y, Farhi SL, Klapoetke NC, Werley CA, Kapoor V, Zou P, Kralj JM, Maclaurin D, Smedemark-Margulies N, Saulnier JL, Boulting GL, Straub C, Cho YK, Melkonian M, Wong GKS, Harrison DJ, Murthy VN, Sabatini BL, Boyden ES, Campbell RE, Cohen AE, Nature Methods 2014 (HEK293 cells, cultured rat hippocampal neurons, in vitro) - [Photoactivated voltage imaging in tissue with an archaerhodopsin-derived reporter](https://doi.org/10.1126/sciadv.abe3216) — Chien MP, Brinks D, Testa-Silva G, Tian H, Brooks FP, Adam Y, Bloxham B, Gmeiner B, Kheifets S, Cohen AE, Science Advances 2021 (Cultured rat hippocampal neurons, acute mouse brain slices, in vitro/in vivo) - [Rational design of far-red archaerhodopsin-3-based fluorescent genetically encoded voltage indicators: from elucidation of the fluorescence mechanism in Archers to novel red-shifted variants](https://doi.org/10.1021/acsphyschemau.3c00073) — Nikolaev DM, Mironov VN, Metelkina EM, et al., ACS Physical Chemistry Au 2024 (Computational modeling and HEK293T cells, in vitro) - [Archaerhodopsin 3 is an ideal template for the engineering of highly fluorescent optogenetic reporters](https://doi.org/10.1039/D4SC05120C) — Herasymenko K, Walisinghe D, Konno M, Barneschi L, de Waele I, Sliwa M, Inoue K, Olivucci M, Haacke S, Chemical Science 2025 (Protein engineering and spectroscopic characterization) - [Semirational protein engineering yields archaerhodopsin-3-based fluorescent genetically encoded voltage indicators with enhanced brightness and red shifted absorption bands](https://doi.org/10.1021/cbe.5c00069) — Nikolaev DM, Metelkina EM, Domskii NA, et al., Chemical & Biomedical Engineering 2025 (HEK293T cells, in vitro) ## Archer1 Archaerhodopsin variant functioning as both a voltage indicator and a light-activated neuronal silencer. - Category: Opsin GEVI - Published: 2014-09-15 — [Nature Communications 2014](https://doi.org/10.1038/ncomms5894) - Derived from: [Arch](https://gevibench.org/gevi/arch) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 627 nm, emission peak 729 nm (Archer1) - Plasmid: [Addgene #60423](https://www.addgene.org/60423/) - Tags: Archaerhodopsin, Red, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.0011× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.5 / 5.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +85% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.78% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 33% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 55.0 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 6 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.5 ms, τ_off 5.5 ms — [Bando 2019, Fig. 1M/1N](https://doi.org/10.1016/j.celrep.2018.12.088) #### ΔF/F per 100 mV - +85%, 1P — [Flytzanis 2014, Fig. 1d](https://doi.org/10.1038/ncomms5894) #### ΔF/F per action potential - 33%, 1P — [Flytzanis 2014, Fig. 3e](https://doi.org/10.1038/ncomms5894) #### Brightness comparisons - 1× the brightness of QuasAr2 — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 5× the brightness of Arch — [Flytzanis 2014, Fig. 1a](https://doi.org/10.1038/ncomms5894) - 0.00367× the brightness of EGFP — [Nikolaev 2025, Table 2](https://doi.org/10.1021/cbe.5c00069) #### Photobleaching - t75% = 150 s at 2200 mW/mm², 1P — [Piatkevich 2018, Fig. 2i](https://doi.org/10.1038/s41589-018-0004-9) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -19%; -70 mV: 0%; -50 mV: 20%; -25 mV: 42%; 0 mV: 67%; 25 mV: 84%; 50 mV: 105% — [Flytzanis 2014, Fig. 1d](https://doi.org/10.1038/ncomms5894) ### Research papers using Archer1 (6) - [Archaerhodopsin variants with enhanced voltage-sensitive fluorescence in mammalian and Caenorhabditis elegans neurons](https://doi.org/10.1038/ncomms5894) — Flytzanis NC, Bedbrook CN, Chiu H, Engqvist MKM, Xiao C, Chan KY, Sternberg PW, Arnold FH, Gradinaru V, Nature Communications 2014 (Cultured rat hippocampal neurons, in vitro; C. elegans AWC-ON neurons, in vivo) - [A robotic multidimensional directed evolution approach applied to fluorescent voltage reporters](https://doi.org/10.1038/s41589-018-0004-9) — Piatkevich KD, Jung EE, Straub C, Linghu C, Park D, Suk HJ, Hochbaum DR, Goodwin D, Pnevmatikakis E, Pak N, et al., Nature Chemical Biology 2018 (HEK293T cells and cultured rat hippocampal neurons, in vitro) - [Comparative Evaluation of Genetically Encoded Voltage Indicators](https://doi.org/10.1016/j.celrep.2018.12.088) — Bando Y, Sakamoto M, Kim S, Ayzenshtat I, Yuste R, Cell Reports 2019 (Mouse cortical neurons, in vitro (excluded from in vivo due to low brightness under LED/2P excitation)) - [Screening and Cellular Characterization of Genetically Encoded Voltage Indicators Based on Near-Infrared Fluorescent Proteins](https://doi.org/10.1021/acschemneuro.0c00046) — Monakhov MV, Matlashov ME, Colavita M, Song C, Shcherbakova DM, Antic SD, Verkhusha VV, Knöpfel T, ACS Chemical Neuroscience 2020 (HEK293T cells and cultured rat hippocampal neurons, in vitro) - [Rational Design of Far-Red Archaerhodopsin-3-Based Fluorescent Genetically Encoded Voltage Indicators: from Elucidation of the Fluorescence Mechanism in Archers to Novel Red-Shifted Variants](https://doi.org/10.1021/acsphyschemau.3c00073) — Nikolaev DM, et al., ACS Physical Chemistry Au 2024 (Computational modeling and HEK293T cells, in vitro) - [Semirational Protein Engineering Yields Archaerhodopsin-3-Based Fluorescent Genetically Encoded Voltage Indicators with Enhanced Brightness and Red Shifted Absorption Bands](https://doi.org/10.1021/cbe.5c00069) — Nikolaev DM, et al., Chem & Bio Engineering 2025 (E. coli and HEK293T cells, in vitro) ## Archer2 Archaerhodopsin variant that further suppresses photocurrents (~99× vs Arch WT, producing no peak current) at the expense of slower kinetics and lower sensitivity (60% ΔF/F per 100 mV) than its sibling Archer1 (~55×). - Category: Opsin GEVI - Published: 2014-09-15 — [Nature Communications 2014](https://doi.org/10.1038/ncomms5894) - Derived from: [Arch](https://gevibench.org/gevi/arch) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 640 nm, emission peak 731 nm (Archer2) - Tags: Archaerhodopsin, Red, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.0016× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | — | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +60% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.45% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 3 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### ΔF/F per 100 mV - +60%, 1P — [Flytzanis 2014, Fig. 1d](https://doi.org/10.1038/ncomms5894) #### Brightness comparisons - 3× the brightness of Arch — [Flytzanis 2014, Fig. 1a](https://doi.org/10.1038/ncomms5894) - 0.0163× the brightness of EGFP — [Nikolaev 2025, Table 2](https://doi.org/10.1021/cbe.5c00069) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -15%; -80 mV: -4%; -70 mV: 0%; -60 mV: 5%; -50 mV: 11%; -40 mV: 18%; -20 mV: 30%; 0 mV: 42%; 20 mV: 54%; 30 mV: 58%; 50 mV: 70% — [Flytzanis 2014, Fig. 1d](https://doi.org/10.1038/ncomms5894) ### Research papers using Archer2 (3) - [Archaerhodopsin variants with enhanced voltage-sensitive fluorescence in mammalian and Caenorhabditis elegans neurons](https://doi.org/10.1038/ncomms5894) — Flytzanis NC, Bedbrook CN, Chiu H, Engqvist MKM, Xiao C, Chan KY, Sternberg PW, Arnold FH, Gradinaru V, Nature Communications 2014 (Cultured rat hippocampal neurons, in vitro) - [Rational Design of Far-Red Archaerhodopsin-3-Based Fluorescent Genetically Encoded Voltage Indicators: from Elucidation of the Fluorescence Mechanism in Archers to Novel Red-Shifted Variants](https://doi.org/10.1021/acsphyschemau.3c00073) — Nikolaev DM, et al., ACS Physical Chemistry Au 2024 (Computational modeling and HEK293T cells, in vitro) - [Semirational Protein Engineering Yields Archaerhodopsin-3-Based Fluorescent Genetically Encoded Voltage Indicators with Enhanced Brightness and Red Shifted Absorption Bands](https://doi.org/10.1021/cbe.5c00069) — Nikolaev DM, et al., Chem & Bio Engineering 2025 (E. coli and HEK293T cells, in vitro) ## Archon1 Robotically evolved archaerhodopsin variant with improved brightness, millisecond kinetics, and exceptional photostability for long-duration recordings. - Category: Opsin GEVI - Published: 2018-02-26 — [Nature Chemical Biology 2018](https://doi.org/10.1038/s41589-018-0004-9) - Derived from: [QuasAr2](https://gevibench.org/gevi/quasar2) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 586 nm, emission peak 693 nm (Archon1) - Two-photon compatible: no - Plasmid: [Addgene #108423](https://www.addgene.org/108423/) - Tags: Archaerhodopsin, Red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.0039× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.5 / 2.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +43% (median of 4 measurements: +59.3%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.4% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 30% (median of 3 measurements: 30%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 2.6 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 7.0 h | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 16 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.51 ms, τ_off 2.53 ms at 32°C — [Piatkevich 2018, Table S1](https://doi.org/10.1038/s41589-018-0004-9) - τ_on 3.1 ms, τ_off 2.66 ms at 30°C — [Tian 2023, Ext. Fig. 4e](https://doi.org/10.1038/s41592-022-01743-5) #### ΔF/F per 100 mV - +43%, 1P — [Piatkevich 2018, Fig. 2e](https://doi.org/10.1038/s41589-018-0004-9) - +48.6%, 1P — [Milosevic 2020, Fig. 2D](https://doi.org/10.1523/ENEURO.0060-20.2020) - +81%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - +70%, 1P — [Tian 2023, Ext. Fig. 4c](https://doi.org/10.1038/s41592-022-01743-5) #### ΔF/F per action potential - 30%, 1P — [Piatkevich 2018, Fig. 2h](https://doi.org/10.1038/s41589-018-0004-9) - 30%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 22.4%, 1P — [Piatkevich 2018, Table S2](https://doi.org/10.1038/s41589-018-0004-9) #### AP width (FWHM) - 2.5 ms at 2300 Hz sampling, Mouse, cultured hippocampal neurons, in vitro, 1P — [Piatkevich 2018, Fig. 2h](https://doi.org/10.1038/s41589-018-0004-9) - 6.1 ms at 500 Hz sampling, Mouse, cultured hippocampal neurons, in vitro, 1P — [Milosevic 2020, Fig. 1D](https://doi.org/10.1523/ENEURO.0060-20.2020) - 2.7 ms at 1000 Hz sampling, Mouse, visual cortex layer-1 NDNF interneurons, in vivo, 1P — [Tian 2023, Fig. 4d](https://doi.org/10.1038/s41592-022-01743-5) - 1.1 ms at 2000 Hz sampling, Mouse, hippocampal CA1 parvalbumin interneurons, in vivo, 1P — [Tian 2023, Fig. 4h](https://doi.org/10.1038/s41592-022-01743-5) #### Brightness comparisons - 2.78× the brightness of QuasAr2 — [Piatkevich 2018, Fig. 2b](https://doi.org/10.1038/s41589-018-0004-9) - 0.588× the brightness of QuasAr6a — [Tian 2023, Ext. Fig. 4b](https://doi.org/10.1038/s41592-022-01743-5) - 0.5× the brightness of QuasAr6b — [Tian 2023, Ext. Fig. 4b](https://doi.org/10.1038/s41592-022-01743-5) - 0.005076142131979695× the brightness of ASAP3 — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 0.14285714285714285× the brightness of nirButterfly — [Song 2024, Fig. 2b](https://doi.org/10.1117/1.NPh.11.2.024201) - 0.3333333333333333× the brightness of NovArch — [Chien 2021, Fig. S1C](https://doi.org/10.1126/sciadv.abe3216) #### Photobleaching - t75% = 601 s (extrapolated) at 4200 mW/mm², 1P — [Tian 2023, Ext. Fig. 4f](https://doi.org/10.1038/s41592-022-01743-5) - curve only (did not reach 75% within the measured window) at 800 mW/mm², 1P — [Piatkevich 2018, Fig. 2i](https://doi.org/10.1038/s41589-018-0004-9) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -12%; -80 mV: -5%; -60 mV: 3%; -40 mV: 12%; -20 mV: 21%; 0 mV: 30%; 20 mV: 40%; 40 mV: 50%; 60 mV: 60% — [Piatkevich 2018, Fig. 2e](https://doi.org/10.1038/s41589-018-0004-9) ### Research papers using Archon1 (16) - [A robotic multidimensional directed evolution approach applied to fluorescent voltage reporters](https://doi.org/10.1038/s41589-018-0004-9) — Piatkevich KD, Jung EE, Straub C, Linghu C, Park D, Suk HJ, Hochbaum DR, Goodwin D, Pnevmatikakis E, Pak N, Kawashima T, Yang CT, Rhoades JL, Shemesh O, Asano S, Yoon YG, Freifeld L, Saulnier JL, Riegler C, Engert F, Hughes T, Drobizhev M, Szabo B, Ahrens MB, Flavell SW, Sabatini BL, Boyden ES, Nature Chemical Biology 2018 (HEK293T cells, cultured mouse hippocampal neurons, mouse cortex brain slices, zebrafish larvae, C. elegans, in vitro/in vivo) - [Rhodopsin-based voltage imaging tools for use in muscles and neurons of Caenorhabditis elegans](https://doi.org/10.1073/pnas.1902443116) — Azimi Hashemi N, Bergs ACF, Schüler C, Scheiwe AR, Steuer Costa W, Bach M, Liewald JF, Gottschalk A, Proceedings of the National Academy of Sciences 2019 (C. elegans, body wall muscle, pharyngeal muscle, neurons, in vivo) - [In Vitro Testing of Voltage Indicators: Archon1, ArcLightD, ASAP1, ASAP2s, ASAP3b, Bongwoori-Pos6, BeRST1, FlicR1, and Chi-VSFP-Butterfly](https://doi.org/10.1523/ENEURO.0060-20.2020) — Milosevic MM, Jang J, McKimm EJ, Zhu MH, Antic SD, eNeuro 2020 (HEK293 cells, in vitro; Mouse cortical neurons, in vitro) - [Voltage Imaging of Cardiac Cells and Tissue Using the Genetically Encoded Voltage Sensor Archon1](https://doi.org/10.1016/j.isci.2020.100974) — Shroff SN, Das SL, Tseng HA, Noueihed J, Fernandez F, White JA, Chen CS, Han X, iScience 2020 (hiPSC-derived cardiomyocytes, in vitro; 3D engineered cardiac tissue, in vitro) - [High-fidelity estimates of spikes and subthreshold waveforms from 1-photon voltage imaging in vivo](https://doi.org/10.1016/j.celrep.2021.108954) — Xie ME, Adam Y, Fan LZ, Böhm UL, Kinsella I, Zhou D, Rozsa M, Singh A, Svoboda K, Paninski L, Cohen AE, Cell Reports 2021 (Mouse hippocampus CA1 pyramidal neurons, in vivo; Mouse cortex layer 1 interneurons, in vivo) - [Plakophilin-2 truncating variants impair cardiac contractility by disrupting sarcomere stability and organization](https://doi.org/10.1126/sciadv.abh3995) — Zhang K, Cloonan PE, Sundaram S, Liu F, Das SL, Ewoldt JK, Bays JL, Tomp S, Toepfer CN, Marsiglia JDC, Gorham J, Reichart D, Eyckmans J, Seidman JG, Seidman CE, Chen CS, Science Advances 2021 (hiPSC-derived cardiomyocytes, in vitro) - [Studying Synaptically Evoked Cortical Responses ex vivo With Combination of a Single Neuron Recording (Whole-Cell) and Population Voltage Imaging (Genetically Encoded Voltage Indicator)](https://doi.org/10.3389/fnins.2021.773883) — Jang J, Zhu MH, Jogdand AH, Antic SD, Frontiers in Neuroscience 2021 (Mouse cortex layer 2/3 pyramidal neurons, acute brain slices, in vitro) - [Neuronal activity drives pathway-specific depolarization of peripheral astrocyte processes](https://doi.org/10.1038/s41593-022-01049-x) — Armbruster M, Naskar S, Garcia JP, Sommer M, Kim E, Adam Y, Haydon PG, Boyden ES, Cohen AE, Dulla CG, Nature Neuroscience 2022 (Mouse cortex astrocytes, acute brain slices, in vitro) - [Voltage imaging identifies spinal circuits that modulate locomotor adaptation in zebrafish](https://doi.org/10.1016/j.neuron.2022.01.001) — Böhm UL, Kimura Y, Kawashima T, Ahrens MB, Higashijima S, Engert F, Cohen AE, Neuron 2022 (Zebrafish larvae, spinal cord glutamatergic neurons, in vivo) - [Video-based pooled screening yields improved far-red genetically encoded voltage indicators](https://doi.org/10.1038/s41592-022-01743-5) — Tian H, Davis HC, Wong-Campos JD, Park P, Fan LZ, Gmeiner B, Begum S, Werley CA, Borja GB, Upadhyay H, Shah H, Jacques J, Qi Y, Parot V, Deisseroth K, Cohen AE, Nature Methods 2023 (Mouse cortex NDNF neurons, in vivo; Mouse hippocampus PV neurons, in vivo; Cultured neurons, in vitro) - [Characterization of two near-infrared genetically encoded voltage indicators](https://doi.org/10.1117/1.NPh.11.2.024201) — Song C, Matlashov ME, Shcherbakova DM, Antic SD, Verkhusha VV, Knöpfel T, Neurophotonics 2024 (Mouse hippocampal CA3 slices, acute brain slices, in vitro) - [Subthreshold electric fields bidirectionally modulate neurotransmitter release through axon polarization](https://doi.org/10.1016/j.brs.2025.103006) — Aberra AS, Miles MW, Hoppa MB, Brain Stimulation 2025 (Rat hippocampal neurons, dissociated culture, in vitro) - [Ultrafast two-photon imaging of a high-gain voltage indicator in awake behaving mice](https://doi.org/10.1016/j.cell.2019.11.004) — Villette V, Chavarha M, Dimov IK, Bradley J, Pradhan L, Mathieu B, Evans SW, Chamberland S, Shi D, Yang R, Kim BB, Ayon A, Jalil A, St-Pierre F, Schnitzer MJ, Bi G, Toth K, Ding J, Dieudonne S, Lin MZ, Cell 2019 (HEK293 cells, cultured neurons, mouse brain in vivo) - [Screening and cellular characterization of genetically encoded voltage indicators based on near-infrared fluorescent proteins](https://doi.org/10.1021/acschemneuro.0c00046) — Monakhov MV, Matlashov ME, Colavita M, Song C, Shcherbakova DM, Antic SD, Verkhusha VV, Knopfel T, ACS Chemical Neuroscience 2020 (HEK293T cells and cultured mouse hippocampal neurons, in vitro) - [QuasAr Odyssey: the origin of fluorescence and its voltage sensitivity in microbial rhodopsins](https://doi.org/10.1038/s41467-022-33084-4) — Silapetere A, Hwang S, Hontani Y, Fernandez Lahore RG, Balke J, Escobar FV, Tros M, Konold PE, Matis R, Croce R, Walla PJ, Hildebrandt P, Alexiev U, Kennis JTM, Sun H, Utesch T, Hegemann P, Nature Communications 2022 (ND7/23 cells, E. coli, in vitro) - [Detection of Membrane Potential-Dependent Rhodopsin Fluorescence Using Low-Intensity Light Emitting Diode for Long-Term Imaging](https://doi.org/10.1021/acsomega.2c06980) — Kawanishi S, Kojima K, Shibukawa A, Sakamoto M, Sudo Y, ACS Omega 2023 (HEK293 and PC12 cells, in vitro) ## Archon2 Sibling variant of Archon1 with superior membrane localization and brightness at the cost of reduced sensitivity. - Category: Opsin GEVI - Published: 2018-02-26 — [Nature Chemical Biology 2018](https://doi.org/10.1038/s41589-018-0004-9) - Derived from: [QuasAr2](https://gevibench.org/gevi/quasar2) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 586 nm, emission peak 693 nm (Archon2) - Plasmid: [Addgene #108421](https://www.addgene.org/108421/) - Tags: Archaerhodopsin, Red, Near-infrared ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.0067× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.0 / 0.72 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +20% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.2% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 18% (median of 2 measurements: 13.7%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 2.4 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 1.2 h | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 4 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.05 ms, τ_off 0.72 ms at 32°C — [Piatkevich 2018, Table S1](https://doi.org/10.1038/s41589-018-0004-9) #### ΔF/F per 100 mV - +20%, 1P — [Piatkevich 2018, Fig. 1g](https://doi.org/10.1038/s41589-018-0004-9) #### ΔF/F per action potential - 18%, 1P — [Piatkevich 2018, Table S1](https://doi.org/10.1038/s41589-018-0004-9) - 9.4%, 1P — [Piatkevich 2018, Table S2](https://doi.org/10.1038/s41589-018-0004-9) #### AP width (FWHM) - 2.4 ms at 2300 Hz sampling, Mouse, cultured hippocampal neurons, in vitro, 1P — [Piatkevich 2018, Fig. S16e](https://doi.org/10.1038/s41589-018-0004-9) #### Brightness comparisons - 8.01× the brightness of QuasAr2 — [Piatkevich 2018, Fig. 2b](https://doi.org/10.1038/s41589-018-0004-9) #### Photobleaching - t75% = 534 s at 800 mW/mm², 1P — [Piatkevich 2018, Fig. 2i](https://doi.org/10.1038/s41589-018-0004-9) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -7%; -80 mV: -2%; -70 mV: 0%; -60 mV: 2%; -40 mV: 6%; -20 mV: 10%; 0 mV: 13%; 20 mV: 17%; 40 mV: 20%; 60 mV: 23% — [Piatkevich 2018, Fig. S16c](https://doi.org/10.1038/s41589-018-0004-9) ### Research papers using Archon2 (4) - [A robotic multidimensional directed evolution approach applied to fluorescent voltage reporters](https://doi.org/10.1038/s41589-018-0004-9) — Piatkevich KD, Jung EE, Straub C, Linghu C, Park D, Suk HJ, Hochbaum DR, Goodwin D, Pnevmatikakis E, Pak N, Kawashima T, Yang CT, Rhoades JL, Shemesh O, Asano S, Yoon YG, Freifeld L, Saulnier JL, Riegler C, Engert F, Hughes T, Drobizhev M, Szabo B, Ahrens MB, Bhatt DH, Schreiter ER, Sabatini BL, Bhatt DH, Boyden ES, Nature Chemical Biology 2018 (HEK293T cells, in vitro; Mouse cortex, acute brain slices; Cultured neurons, in vitro) - [Screening and Cellular Characterization of Genetically Encoded Voltage Indicators Based on Near-Infrared Fluorescent Proteins](https://doi.org/10.1021/acschemneuro.0c00046) — Monakhov MV, Matlashov ME, Colavita M, Song C, Shcherbakova DM, Antic SD, Bhatt DH, Verkhusha VV, Knöpfel T, ACS Chemical Neuroscience 2020 (HEK293T cells, in vitro; Cultured hippocampal neurons, in vitro) - [Absorption and Emission Spectroscopic Investigation of the Thermal Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor Archon2](https://doi.org/10.3390/ijms21186576) — Penzkofer A, Silapetere A, Hegemann P, International Journal of Molecular Sciences 2020 (Purified protein in Tris buffer, in vitro spectroscopy) - [Photocycle dynamics of the Archaerhodopsin 3 based fluorescent voltage sensor Archon2](https://doi.org/10.1016/j.jphotobiol.2021.112331) — Penzkofer A, Silapetere A, Hegemann P, Journal of Photochemistry and Photobiology B: Biology 2021 (Purified protein in Tris buffer, in vitro spectroscopy) ## ArcLight Classic GEVI using a VSD fused to pH-sensitive GFP. - Category: VSD-single FP - Published: 2012-09-06 — [Neuron 2012](https://www.cell.com/neuron/fulltext/S0896-6273(12)00704-0) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 488 nm, emission peak 511 nm (ArcLight) - Two-photon compatible: yes - Plasmid: [Addgene #36856](https://www.addgene.org/36856/) - Tags: pHluorin ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.66× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 25 / 30 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -35% (median of 4 measurements: −31.8%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.47% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 3.2% (median of 6 measurements: 2.95%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 6.6 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 7.3 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 53 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 25 ms, τ_off 38 ms at 33-35°C — [Jin 2012, Fig. S3B](https://doi.org/10.1016/j.neuron.2012.06.040) - τ_on 28 ms, τ_off 104 ms at 22-23°C — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - τ_on 25 ms, τ_off 21.5 ms at 34°C — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) - τ_on 176 ms, τ_off 174 ms at 23°C — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### ΔF/F per 100 mV - -35%, 1P — [Jin 2012, Fig. 2C](https://doi.org/10.1016/j.neuron.2012.06.040) - -29.6%, 1P — [Milosevic 2020, Fig. 2D](https://doi.org/10.1523/ENEURO.0060-20.2020) - -32%, 1P — [Hochbaum 2014, Fig. S6](https://doi.org/10.1038/nmeth.3000) - -31.6%, 1P — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### ΔF/F per action potential - 3.2%, 1P — [Jin 2012, Fig. 3](https://doi.org/10.1016/j.neuron.2012.06.040) - 3.2%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 2.2%, 1P — [St-Pierre 2014, Fig. 1g](https://doi.org/10.1038/nn.3709) - 2.6%, 1P — [Platisa 2017, Main text](https://doi.org/10.1021/acschemneuro.6b00234) - 2.7%, 1P — [Lee 2017, Table 3](https://doi.org/10.1038/s41598-017-08731-2) - 8.2%, 1P — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### AP width (FWHM) - 6.5 ms at undefined Hz sampling, Cultured rat hippocampal neurons, in vitro, 1P, 22°C — [St-Pierre 2014, Fig. 1f](https://doi.org/10.1038/nn.3709) - 70.6 ms at 1000 Hz sampling, Cultured rat hippocampal neurons, in vitro, 1P — [Abdelfattah 2016, Fig. 5E](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) - 6.6 ms at 440 Hz sampling, Cultured neurons, in vitro, 1P — [Gong 2014, Fig. 5c](https://doi.org/10.1038/ncomms4674) #### Brightness comparisons - 0.655× the brightness of EGFP — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 1.639344262295082× the brightness of ASAP1 — [Milosevic 2020, Fig. 2F](https://doi.org/10.1523/ENEURO.0060-20.2020) - 1.4662756598240467× the brightness of ASAP3 — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 3.4482758620689657× the brightness of Bongwoori — [Lee 2017, Table 3](https://doi.org/10.1038/s41598-017-08731-2) - 0.3333333333333333× the brightness of MacQ-mCitrine — [Gong 2014, Main text](https://doi.org/10.1038/ncomms4674) - 0.3333333333333333× the brightness of MacQ-mOrange2 — [Gong 2014, Main text](https://doi.org/10.1038/ncomms4674) - 1.4771048744460855× the brightness of Marina — [Platisa 2017, Main text](https://doi.org/10.1021/acschemneuro.6b00234) #### Photobleaching - t75% = 177 s at 1 mW/mm², 1P — [Lee 2017, Fig. S1](https://doi.org/10.1038/s41598-017-08731-2) - t75% = 64 s at 11 mW/mm², 1P — [Chamberland 2017, Fig. 1—figure supplement 3A](https://doi.org/10.7554/eLife.25690) - t75% = 42 s at 18 mW/mm², 1P — [Platisa 2017, Fig. 3C](https://doi.org/10.1021/acschemneuro.6b00234) - t75% = 56 s at 100 mW/mm², 1P — [Abdelfattah 2016, Fig. 3I](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 16%; -70 mV: 0%; -40 mV: -12%; 30 mV: -30%; 100 mV: -41% — [Milosevic 2020, Fig. 2C](https://doi.org/10.1523/ENEURO.0060-20.2020) ### Research papers using ArcLight (53) - [Single action potentials and subthreshold electrical events imaged in neurons with a fluorescent protein voltage probe](https://doi.org/10.1016/j.neuron.2012.06.040) — Jin L, Han Z, Platisa J, Wooltorton JRA, Cohen LB, Pieribone VA, Neuron 2012 (HEK293 cells, cultured mouse hippocampal neurons, in vitro) - [Genetically targeted optical electrophysiology in intact neural circuits](https://doi.org/10.1016/j.cell.2013.07.027) — Cao G, et al., Cell 2013 (Drosophila brain neurons, in vivo) - [Fluorescent protein voltage probes derived from ArcLight that respond to membrane voltage changes with fast kinetics](https://doi.org/10.1371/journal.pone.0081295) — Han Z, et al., PLoS One 2013 (HEK293 cells and cultured rat hippocampal neurons, in vitro) - [Rapid cellular phenotyping of human pluripotent stem cell-derived cardiomyocytes using a genetically encoded fluorescent voltage sensor](https://doi.org/10.1016/j.stemcr.2014.01.003) — Leyton-Mange JS, et al., Stem Cell Reports 2014 (Human iPSC-derived cardiomyocytes, in vitro) - [Imaging neural spiking in brain tissue using FRET-opsin protein voltage sensors](https://doi.org/10.1038/ncomms4674) — Gong Y, et al., Nature Communications 2014 (Cultured neurons, brain slices, mouse cerebellum in vivo) - [Mechanistic studies of the genetically encoded fluorescent protein voltage probe ArcLight](https://doi.org/10.1371/journal.pone.0113873) — Han Z, et al., PLoS One 2014 (HEK293 cells, in vitro) - [Monitoring brain activity with protein voltage and calcium sensors](https://doi.org/10.1038/srep10212) — Storace DA, et al., Scientific Reports 2015 (Mouse olfactory bulb, in vivo) - [Two-photon lifetime imaging of voltage indicating proteins as a probe of absolute membrane voltage](https://doi.org/10.1016/j.bpj.2015.07.038) — Brinks D, et al., Biophysical Journal 2015 (HEK293 cells, in vitro) - [Monitoring human-induced pluripotent stem cell-derived cardiomyocytes with genetically encoded calcium and voltage fluorescent reporters](https://doi.org/10.1016/j.stemcr.2015.08.009) — Shinnawi R, et al., Stem Cell Reports 2015 (Human iPSC-derived cardiomyocytes, in vitro) - [Dual optical recordings for action potentials and calcium handling in induced pluripotent stem cell models of cardiac arrhythmias](https://doi.org/10.5966/sctm.2014-0245) — Song L, et al., Stem Cells Translational Medicine 2015 (Human iPSC-derived cardiomyocytes (Timothy syndrome), in vitro) - [Expression and testing in plants of ArcLight, a genetically-encoded voltage indicator used in neuroscience research](https://doi.org/10.1186/s12870-015-0633-z) — Matzke AJ, et al., BMC Plant Biology 2015 (Nicotiana benthamiana and Arabidopsis thaliana, in vivo) - [Single-molecule fluorimetry and gating currents inspire an improved optical voltage indicator (ArcLightning)](https://doi.org/10.7554/eLife.10482) — Treger JS, et al., eLife 2015 (HEK293 cells, Xenopus oocytes, in vitro) - [Ziram, a pesticide associated with increased risk for Parkinson's disease, differentially affects the presynaptic function of aminergic and glutamatergic nerve terminals](https://doi.org/10.1016/j.expneurol.2015.09.017) — Martin CA, et al., Experimental Neurology 2016 (Drosophila neuromuscular junction, ex vivo) - [Optogenetic monitoring of synaptic activity with genetically encoded voltage indicators](https://doi.org/10.3389/fnsyn.2016.00022) — Nakajima R, et al., Frontiers in Synaptic Neuroscience 2016 (Mouse olfactory bulb brain slices and in vivo) - [Directed evolution of key residues in fluorescent protein inverses the polarity of voltage sensitivity in ArcLight (Marina)](https://doi.org/10.1021/acschemneuro.6b00234) — Platisa J, et al., ACS Chemical Neuroscience 2017 (HEK293 cells, in vitro) - [Genetically expressed voltage sensor ArcLight for imaging large scale cortical activity in the anesthetized and awake mouse](https://doi.org/10.1117/1.NPh.4.3.031212) — Borden PY, et al., Neurophotonics 2017 (Mouse somatosensory cortex (barrel cortex), in vivo) - [Attenuation of synaptic potentials in dendritic spines](https://doi.org/10.1016/j.celrep.2017.07.012) — Kwon T, et al., Cell Reports 2017 (Cultured rat hippocampal neurons, in vitro (two-photon)) - [Improving a genetically encoded voltage indicator by modifying the cytoplasmic charge composition (Bongwoori-R3)](https://doi.org/10.1038/s41598-017-08731-2) — Lee S, et al., Scientific Reports 2017 (HEK293 cells and cultured rat hippocampal neurons, in vitro) - [MicroRNA-92a is a circadian modulator of neuronal excitability in Drosophila](https://doi.org/10.1038/ncomms14707) — Chen X, et al., Nature Communications 2017 (Drosophila PDF pacemaker neurons, in vivo) - [Human induced pluripotent stem cell-derived cardiac cell sheets expressing genetically encoded voltage indicator for pharmacological and arrhythmia studies](https://doi.org/10.1016/j.stemcr.2018.04.006) — Shaheen N, et al., Stem Cell Reports 2018 (Human iPSC-derived cardiac cell sheets, in vitro) - [A dimeric fluorescent protein yields a bright, red-shifted GEVI capable of population signals in brain slice (Ilmol)](https://doi.org/10.1038/s41598-018-33297-y) — Yi B, et al., Scientific Reports 2018 (HEK293 cells, cultured neurons, mouse hippocampal brain slices) - [Mapping of excitatory and inhibitory postsynaptic potentials of neuronal populations in hippocampal slices using the GEVI, ArcLight](https://doi.org/10.1088/1361-6463/aae2e3) — Nakajima R, et al., Journal of Physics D: Applied Physics 2018 (Mouse hippocampal CA1 brain slices, ex vivo) - [Optical consequences of a genetically-encoded voltage indicator with a pH sensitive fluorescent protein](https://doi.org/10.1016/j.neures.2018.10.006) — Kang BE, et al., Neuroscience Research 2019 (HEK293 cells and cultured hippocampal neurons, in vitro) - [Comparative evaluation of genetically encoded voltage indicators](https://doi.org/10.1016/j.celrep.2018.12.088) — Bando Y, et al., Cell Reports 2019 (HEK293 cells, cultured neurons, mouse visual cortex in vivo) - [Using genetically encoded voltage indicators (GEVIs) to study the input-output transformation of the mammalian olfactory bulb](https://doi.org/10.3389/fncel.2019.00342) — Storace DA, et al., Frontiers in Cellular Neuroscience 2019 (Mouse olfactory bulb, in vivo) - [Single-cell RNA-sequencing and optical electrophysiology of human iPSC-derived cardiomyocytes reveal discordance between cardiac subtype-associated gene expression and electrophysiological phenotypes](https://doi.org/10.1089/scd.2019.0030) — Biendarra-Tiegs SM, et al., Stem Cells and Development 2019 (Human iPSC-derived cardiomyocytes, in vitro) - [Characterization of the CACNA1C-R518C missense mutation in the pathobiology of long-QT syndrome using human iPSC cardiomyocytes](https://doi.org/10.1161/CIRCGEN.119.002534) — Estes SI, et al., Circulation: Genomic and Precision Medicine 2019 (Human iPSC-derived cardiomyocytes (long-QT syndrome), in vitro) - [Human induced pluripotent stem cell line with genetically encoded fluorescent voltage indicator generated via CRISPR](https://doi.org/10.1002/stem.3085) — Sun YH, et al., Stem Cells 2020 (Human iPSC-derived cardiomyocytes (CRISPR knock-in), in vitro) - [Human iPSC-derived non-cardiomyocytes modulate cardiac electrophysiological maturation through connexin 43-mediated cell-cell interactions](https://doi.org/10.1089/scd.2019.0098) — Biendarra-Tiegs SM, et al., Stem Cells and Development 2020 (Human iPSC-derived cardiomyocytes and non-cardiomyocytes co-cultures, in vitro) - [Real-time detection of changes in yeast plasma membrane potential using genetically encoded voltage indicator proteins](https://doi.org/10.1093/femsyr/foaa041) — Limapichat W, et al., FEMS Yeast Research 2020 (Saccharomyces cerevisiae (yeast), in vitro) - [In vitro testing of voltage indicators: Archon1, ArcLightD, ASAP1, ASAP2s, ASAP3b, Bongwoori-Pos6, BeRST1, FlicR1, and Chi-VSFP-Butterfly](https://doi.org/10.1523/ENEURO.0060-20.2020) — Milosevic MM, et al., eNeuro 2020 (HEK293 cells, cultured neurons, mouse brain slices) - [Triclosan disrupts immune cell function by depressing Ca2+ influx following acidification of the cytoplasm](https://doi.org/10.1016/j.taap.2020.115205) — Sangroula S, et al., Toxicology and Applied Pharmacology 2020 (RBL-2H3 mast cells and Jurkat T cells, in vitro) - [Analysing bioelectrical phenomena in the Drosophila ovary with genetic tools](https://doi.org/10.1186/s12861-020-00220-6) — Schotthoefer SK, et al., BMC Developmental Biology 2020 (Drosophila melanogaster ovary follicular epithelium, ex vivo) - [Promise and potential peril with lumacaftor for the trafficking defective type 2 long-QT syndrome-causative variants](https://doi.org/10.1161/CIRCGEN.120.002950) — O'Hare BJ, et al., Circulation: Genomic and Precision Medicine 2020 (Human iPSC-derived cardiomyocytes (LQT2), in vitro) - [GEVI cell-type specific labelling and a manifold learning approach provide evidence for lateral inhibition at the population level in mouse hippocampal CA1](https://doi.org/10.1111/ejn.15177) — Nakajima R, et al., European Journal of Neuroscience 2021 (Mouse hippocampal CA1 brain slices, ex vivo) - [Improving the flexibility of genetically encoded voltage indicators via intermolecular FRET](https://doi.org/10.1016/j.bpj.2021.03.010) — Leong LM, et al., Biophysical Journal 2021 (HEK293 cells, in vitro) - [Mechanism of ArcLight derived GEVIs involves electrostatic interactions that can affect proton wires](https://doi.org/10.1016/j.bpj.2021.03.009) — Kang BE, et al., Biophysical Journal 2021 (HEK293 cells, in vitro) - [Enabling comprehensive optogenetic studies of mouse hearts by simultaneous opto-electrical panoramic mapping and stimulation](https://doi.org/10.1038/s41467-021-26039-8) — Rieger M, et al., Nature Communications 2021 (Transgenic mouse hearts (ArcLight-Q239), ex vivo) - [Studying synaptically evoked cortical responses ex vivo with combination of single neuron recording and population voltage imaging](https://doi.org/10.3389/fnins.2021.773883) — Jang J, et al., Frontiers in Neuroscience 2021 (Mouse cortex brain slices, ex vivo) - [Visualizing oscillations in brain slices with genetically encoded voltage indicators](https://doi.org/10.3389/fnana.2021.741711) — Rhee JK, et al., Frontiers in Neuroanatomy 2021 (Mouse motor cortex brain slices, ex vivo) - [Simultaneous two-photon imaging of action potentials and subthreshold inputs in vivo](https://doi.org/10.1038/s41467-021-27444-9) — Bando Y, et al., Nature Communications 2021 (Mouse visual cortex neurons (ArcLight-ST variant), in vivo) - [Voltage imaging in the olfactory bulb using transgenic mouse lines expressing ArcLight](https://doi.org/10.1038/s41598-021-04482-3) — Platisa J, et al., Scientific Reports 2022 (Transgenic mouse olfactory bulb, in vivo) - [Conserved amino acids residing outside the voltage field can shift the voltage sensitivity and increase the signal speed and size of Ciona based GEVIs](https://doi.org/10.3389/fcell.2022.868143) — Sepehri Rad M, et al., Frontiers in Cell and Developmental Biology 2022 (HEK293 cells, in vitro) - [Recombinant adeno-associated viral vector-mediated gene transfer of hTBX18 generates pacemaker cells from ventricular cardiomyocytes](https://doi.org/10.3390/ijms23169230) — Farraha M, et al., International Journal of Molecular Sciences 2022 (Neonatal rat ventricular cardiomyocytes, in vitro) - [Generation of human iPSC line encoding for ArcLight A242](https://doi.org/10.1016/j.scr.2022.102981) — Vivekanandan R, et al., Stem Cell Research 2023 (Human iPSC line with knock-in ArcLight A242, in vitro) - [Voltage to calcium transformation enhances direction selectivity in Drosophila T4 neurons](https://doi.org/10.1523/JNEUROSCI.2297-22.2023) — Mishra A, et al., Journal of Neuroscience 2023 (Drosophila T4 direction-selective neurons, in vivo (two-photon)) - [Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators](https://doi.org/10.7554/eLife.25690) — Chamberland S, et al., eLife 2017 (Drosophila visual neurons (L2), in vivo; HEK293A cells, in vitro) - [Imaging different cell populations in the mouse olfactory bulb using ArcLight](https://doi.org/10.1117/1.NPh.11.3.033402) — Leong LM, et al., Neurophotonics 2024 (Mouse olfactory bulb (multiple cell types), in vivo) - [Generation of a genetically encoded voltage indicator MARINA reporter human iPS cell line using Cas9](https://doi.org/10.1016/j.scr.2024.103628) — Petruskeviciu-te A, et al., Stem Cell Research 2025 (Human iPSC line with knock-in MARINA, in vitro) - [Ultrafast two-photon imaging of a high-gain voltage indicator in awake behaving mice](https://doi.org/10.1016/j.cell.2019.11.004) — Villette V, et al., Cell 2019 (HEK293 cells, cultured neurons, mouse visual cortex in vivo) - [All-optical electrophysiology in mammalian neurons using engineered microbial rhodopsins](https://doi.org/10.1038/nmeth.3000) — Hochbaum DR, et al., Nature Methods 2014 (HEK293T cells, cultured rat hippocampal neurons, human iPSC-derived neurons) - [High-fidelity optical reporting of neuronal electrical activity with an ultrafast fluorescent voltage sensor](https://doi.org/10.1038/nn.3709) — St-Pierre F, et al., Nature Neuroscience 2014 (HEK293A cells, cultured rat hippocampal neurons, mouse brain slices, in vivo) - [A bright and fast red fluorescent protein voltage indicator that reports neuronal activity in organotypic brain slices](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) — Abdelfattah AS, et al., Journal of Neuroscience 2016 (HEK293 cells, organotypic rat brain slices) ## ASAP1 First ASAP sensor, establishing the VSD/cpGFP architecture for fast, negative-going fluorescence responses to voltage. - Category: VSD-cpGFP GEVI - Published: 2014-04-22 — [Nature Neuroscience 2014](https://doi.org/10.1038/nn.3709) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 490 nm, emission peak 510 nm (ASAP1) - Two-photon compatible: yes - Plasmid: [Addgene #52519](https://www.addgene.org/52519/) - Tags: cpGFP ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.43× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 6.7 / 12 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -17.5% (median of 4 measurements: −24.5%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.21% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 6.3% (median of 4 measurements: 7.45%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 6.2 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 11 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 21 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 29.7 ms, τ_off 29.5 ms at 22°C — [St-Pierre 2014, Fig. 1e](https://doi.org/10.1038/nn.3709) - τ_on 44 ms, τ_off 66.9 ms at 22°C — [Chamberland 2017, Table 1](https://doi.org/10.7554/eLife.25690) - τ_on 6.7 ms, τ_off 11.6 ms at 23°C — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) - τ_on 23.3 ms, τ_off 36.4 ms at 23°C — [Villette 2019, Table S1](https://doi.org/10.1016/j.cell.2019.11.004) #### ΔF/F per 100 mV - -17.5%, 1P — [St-Pierre 2014, Fig. 1d](https://doi.org/10.1038/nn.3709) - -23.3%, 1P — [Chamberland 2017, Fig. 1C](https://doi.org/10.7554/eLife.25690) - -25.7%, 1P — [Milosevic 2020, Fig. 2D](https://doi.org/10.1523/ENEURO.0060-20.2020) - -28.8%, 1P — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### ΔF/F per mV (subthreshold) - 0.21%/mV, 1P (Subthreshold voltage sensitivity ≈ 0.21 %/mV, derived from the Fig. 3b (top) quantification in voltage-clamped cultured rat hippocampal neurons: ASAP1 peak −ΔF/F was 1.20 / 2.05 / 2.85 / 4.52% for simulated subthreshold depolarization waveforms of 5 / 10 / 15 / 20 mV peak amplitude (17 ms peak FWHM, n = 6 neurons, 1P widefield, 22°C). Through-origin least squares over the four points gives 0.213 %/mV (free-intercept fit gives 0.215 %/mV with a ~0 intercept, i.e. the response is linear over this range). Read off the bar graph, so ±~5%. Comparable steady-state chord slope from the HEK293A F−V curve (Fig. 1d, −80 → −60 mV) is 0.31 %/mV; the neuronal waveform value is lower because these are brief transient responses, not steady-state steps. Cross-GEVI: ArcLight Q239 in the same panel gives ≈ 0.13 %/mV (0.80 / 1.63 / 2.12 / 2.28%).) — [St-Pierre 2014, Fig. 3b](https://doi.org/10.1038/nn.3709) #### ΔF/F per action potential - 6.3%, 1P — [St-Pierre 2014, Fig. 4a](https://doi.org/10.1038/nn.3709) - 8.6%, 1P — [Chamberland 2017, Fig. 2I](https://doi.org/10.7554/eLife.25690) - 2.8%, 1P — [Lee 2017, Table 3](https://doi.org/10.1038/s41598-017-08731-2) - 17.8%, 1P — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### AP width (FWHM) - 3.7 ms at 827 Hz sampling, Rat cultured hippocampal neurons, current-triggered single AP, in vitro, 1P, 22°C — [St-Pierre 2014, Fig. 1f](https://doi.org/10.1038/nn.3709) - 3.8 ms at 3700 Hz sampling, Organotypic hippocampal slice cultures, current-triggered single AP, two-photon RAMP (FEVIR), 2P, 22°C — [Chamberland 2017, Fig. 6E](https://doi.org/10.7554/eLife.25690) - 9 ms at 1000 Hz sampling, Rat, cultured hippocampal neurons, in vitro, 1P — [Chamberland 2017, Fig. 2J](https://doi.org/10.7554/eLife.25690) - 8.5 ms at 500 Hz sampling, Mouse, cultured primary cortical/hippocampal neurons (P0.5), in vitro, 1P — [Milosevic 2020, Fig. 1A](https://doi.org/10.1523/ENEURO.0060-20.2020) #### Brightness comparisons - 1× the brightness of ASAP2s — [Chamberland 2017, Fig. S2](https://doi.org/10.7554/eLife.25690) - 0.61× the brightness of ArcLight — [Milosevic 2020, Fig. 2F](https://doi.org/10.1523/ENEURO.0060-20.2020) - 0.94× the brightness of ASAP3 — [Nair 2025, Fig. 2C](https://doi.org/10.1021/acschemneuro.5c00670) #### Photobleaching - t75% = 508 s at 0.12 mW/mm², 1P — [St-Pierre 2014, Fig. S9](https://doi.org/10.1038/nn.3709) - t75% = 52 s at 11 mW/mm², 1P — [Chamberland 2017, Fig. 1—figure supplement 3A](https://doi.org/10.7554/eLife.25690) - t75% = 16 s at 100 mW/mm², 1P — [Abdelfattah 2016, Fig. 3I](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) - t50% = 0.84 s at ~1 mW (950 nm, 2P point scan), 2P — [Abdelfattah 2016, Fig. 4C](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 23.4%; -100 mV: 11.7%; -80 mV: 3.3%; -70 mV: 0%; -60 mV: -2.8%; -40 mV: -6.7%; -20 mV: -9.8%; 0 mV: -12.8%; 30 mV: -17.5%; 50 mV: -21.1% — [St-Pierre 2014, Fig. 1d](https://doi.org/10.1038/nn.3709) ### Research papers using ASAP1 (21) - [High-fidelity optical reporting of neuronal electrical activity with an ultrafast fluorescent voltage sensor](https://doi.org/10.1038/nn.3709) — St-Pierre F, Marshall JD, Yang Y, Gong Y, Schnitzer MJ, Lin MZ, Nature Neuroscience 2014 (HEK293A cells; rat hippocampal neurons, in vitro) - [A Bright and Fast Red Fluorescent Protein Voltage Indicator That Reports Neuronal Activity in Organotypic Brain Slices](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) — Abdelfattah AS, Farhi SL, Zhao Y, Brinks D, Zou P, Ruangkittisakul A, Platisa J, Pieribone VA, Ballanyi K, Cohen AE, Campbell RE, Journal of Neuroscience 2016 (HEK293 cells; rat hippocampal neurons, in vitro) - [Biophysical Characterization of Genetically Encoded Voltage Sensor ASAP1: Dynamic Range Improvement](https://doi.org/10.1016/j.bpj.2017.10.018) — Lee EEL, Bezanilla F, Biophysical Journal 2017 (Xenopus laevis oocytes; rat dorsal root ganglion neurons, in vitro) - [Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators](https://doi.org/10.7554/eLife.25690) — Chamberland S, et al., eLife 2017 (HEK293A cells; mouse hippocampal neurons, in vitro) - [In Vitro Testing of Voltage Indicators: Archon1, ArcLightD, ASAP1, ASAP2s, ASAP3b, Bongwoori-Pos6, BeRST1, FlicR1, and Chi-VSFP-Butterfly](https://doi.org/10.1523/ENEURO.0060-20.2020) — Milosevic MM, et al., eNeuro 2020 (HEK293 cells; mouse brain slices, in vitro) - [Comparative Evaluation of Genetically Encoded Voltage Indicators](https://doi.org/10.1016/j.celrep.2018.12.088) — Bando Y, et al., Cell Reports 2019 (Mouse hippocampal neurons, in vitro) - [Optical interrogation of neuronal circuitry in zebrafish using genetically encoded voltage indicators](https://doi.org/10.1038/s41598-018-23906-1) — Miyazawa H, et al., Scientific Reports 2018 (Zebrafish, cerebellum; spinal cord, in vivo) - [Visualization of Cellular Electrical Activity in Zebrafish Early Embryos and Tumors](https://doi.org/10.3791/57330) — Silic MR, Zhang G, Journal of Visualized Experiments 2018 (Zebrafish embryos; zebrafish tumors, in vivo) - [Real-time detection of yeast membrane potential using ASAP1 voltage indicator](https://doi.org/10.1093/femsyr/foaa041) — Limapichat W, et al., FEMS Yeast Research 2020 (Saccharomyces cerevisiae, in vitro) - [In vivo wide-field voltage imaging in zebrafish with voltage-sensitive dye and genetically encoded voltage indicator](https://doi.org/10.1111/dgd.12744) — Hiyoshi K, et al., Development, Growth & Differentiation 2021 (Zebrafish larvae, cerebellum; spinal cord, in vivo) - [Enabling comprehensive optogenetic studies of mouse hearts by simultaneous opto-electrical panoramic mapping and stimulation](https://doi.org/10.1038/s41467-021-26039-8) — Rieger M, et al., Nature Communications 2021 (Mouse heart, ex vivo) - [In Vitro Matured Human Pluripotent Stem Cell-Derived Cardiomyocytes Form Grafts With Enhanced Structure and Function in Injured Hearts](https://doi.org/10.1161/CIRCULATIONAHA.121.053563) — Dhahri W, et al., Circulation 2022 (Human PSC-derived cardiomyocytes; rat heart, ex vivo) - [Zebrafish Embryos Display Characteristic Bioelectric Signals during Early Development](https://doi.org/10.3390/cells11223586) — Silic MR, et al., Cells 2022 (Zebrafish embryos, in vivo) - [Optogenetic Reporters Delivered as mRNA Facilitate Repeatable Action Potential and Calcium Handling Assessment in Human iPSC-Derived Cardiomyocytes](https://doi.org/10.1093/stmcls/sxac029) — Yiangou L, et al., Stem Cells 2022 (Human iPSC-derived cardiomyocytes, in vitro) - [A fully-automated low-cost cardiac monolayer optical mapping robot](https://doi.org/10.3389/fcvm.2023.1096884) — Lee P, et al., Frontiers in Cardiovascular Medicine 2023 (Human PSC-derived cardiomyocyte monolayers, in vitro) - [Protocol for dual-optical mapping of voltage and calcium sensors in human pluripotent stem cell-derived cardiomyocytes](https://doi.org/10.1016/j.xpro.2025.104044) — Alibhai FJ, et al., STAR Protocols 2025 (Human PSC-derived cardiomyocytes, in vitro) - [Absolute Membrane Potential Recording with ASAP-Type Genetically Encoded Voltage Indicators Using Fluorescence Lifetime Imaging](https://doi.org/10.1021/acschemneuro.5c00670) — Nair AG, et al., ACS Chemical Neuroscience 2025 (HEK293T cells, in vitro) - [Bright and fast multicoloured voltage reporters via electrochromic FRET](https://doi.org/10.1038/ncomms5625) — Zou P, Zhao Y, Douglass AD, Hochbaum DR, Brinks D, Werley CA, Harrison DJ, Campbell RE, Cohen AE, Nature Communications 2014 (HEK293 cells; cultured rat hippocampal neurons, in vitro) - [High-speed recording of neural spikes in awake mice and flies with a fluorescent voltage sensor](https://doi.org/10.1126/science.aab0810) — Gong Y, Huang C, Li JZ, Grewe BF, Zhang Y, Eismann S, Schnitzer MJ, Science 2015 (HEK293 cells; mouse cortex, in vivo; Drosophila, in vivo) - [Ultrafast Two-Photon Imaging of a High-Gain Voltage Indicator in Awake Behaving Mice](https://doi.org/10.1016/j.cell.2019.11.004) — Villette V, Chavarha M, Dimov IK, Bradley J, Pradhan L, Mathieu B, Evans SW, Chamberland S, Shi D, Yang R, Kim BB, Ayon A, Jalil A, St-Pierre F, Schnitzer MJ, Bi G, Toth K, Ding J, Dieudonné S, Lin MZ, Cell 2019 (HEK293A cells; mouse cortex and hippocampus, in vivo) - [Improving a genetically encoded voltage indicator by modifying the cytoplasmic charge composition](https://doi.org/10.1038/s41598-017-08731-2) — Lee S, Geiller T, Jung A, Nakajima R, Song YK, Baker BJ, Scientific Reports 2017 (HEK293 cells, in vitro) ## ASAP2s Higher-sensitivity ASAP1 variant that trades speed for larger fluorescence responses. - Category: VSD-cpGFP GEVI - Published: 2017-07-27 — [eLife 2017](https://doi.org/10.7554/eLife.25690) - Derived from: [ASAP1](https://gevibench.org/gevi/asap1) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 490 nm, emission peak 511 nm (ASAP2s) - Two-photon compatible: yes - Plasmid: [Addgene #101274](https://www.addgene.org/101274/) - Tags: cpGFP, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.43× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 7.8 / 14 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -38.7% (median of 4 measurements: −36%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.15% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 12.2% (median of 3 measurements: 9.6%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 15 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 5.5 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 13 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 30.6 ms, τ_off 65.8 ms at 22°C — [Chamberland 2017, Table 1](https://doi.org/10.7554/eLife.25690) - τ_on 3.58 ms, τ_off 6.99 ms at 32-35°C — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - τ_on 11.99 ms, τ_off 21.07 ms at 32-35°C — [Liu 2022, Table S2](https://doi.org/10.1016/j.cell.2022.07.013) - τ_on 16.71 ms, τ_off 29.51 ms at 21-23°C — [Liu 2022, Table S2](https://doi.org/10.1016/j.cell.2022.07.013) #### ΔF/F per 100 mV - -38.7%, 1P — [Chamberland 2017, Fig. 1C](https://doi.org/10.7554/eLife.25690) - -36%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - -28.5%, 1P — [Lu 2023, Fig. 2c](https://doi.org/10.1038/s41467-023-41975-3) - -33.3%, 2P — [Liu 2022, Fig. 2C](https://doi.org/10.1016/j.cell.2022.07.013) #### ΔF/F per mV (subthreshold) - 0.15%/mV, 2P (Subthreshold voltage sensitivity ≈ 0.15 %/mV, from the Fig. 5G peak-response-vs-depolarization plot in organotypic hippocampal slices under 2P (462 Hz). ASAP2s ΔF/F peaks were ~0.9%/1.35%/2.2%/3.15% for 5/10/15/20 mV subthreshold depolarization waveforms (least-squares slope 0.154 %/mV, read from the bar graph). This is a 2P slice measurement of responses to subthreshold-waveform commands (not a 1P near-rest voltage-clamp ramp), so it may not be directly comparable to 1P subthreshold slopes.) — [Chamberland 2017, Fig. 5G](https://doi.org/10.7554/eLife.25690) #### ΔF/F per action potential - 12.2%, 1P — [Chamberland 2017, Fig. 2I](https://doi.org/10.7554/eLife.25690) - 15%, 2P — [Chamberland 2017, Fig. 4E](https://doi.org/10.7554/eLife.25690) - 7%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) #### AP width (FWHM) - 21.1 ms at 3700 Hz sampling, Organotypic hippocampal slice cultures, current-triggered single AP, two-photon RAMP (FEVIR), 2P, 22°C — [Chamberland 2017, Fig. 6E](https://doi.org/10.7554/eLife.25690) - 17.4 ms at 1000 Hz sampling, Rat, cultured hippocampal neurons, in vitro, 1P — [Chamberland 2017, Fig. 2J](https://doi.org/10.7554/eLife.25690) - 17.3 ms at undefined Hz sampling, Rat, cultured hippocampal neurons, current-evoked single AP, room temperature, in vitro, 1P, 22°C — [Villette 2019, Fig. 2F](https://doi.org/10.1016/j.cell.2019.11.004) - 12.3 ms at 500 Hz sampling, Mouse, cultured hippocampal neurons, current-triggered single AP, in vitro, 1P — [Milosevic 2020, Fig. 1B](https://doi.org/10.1523/ENEURO.0060-20.2020) - 6.7 ms at 987 Hz sampling, HEK293A cells, optical response to a single AP-like command waveform (2-ms FWHM, +30 mV peak, −70 mV baseline), whole-cell voltage clamp, in vitro, 1P, 25°C — [Lu 2023, Fig. 2f](https://doi.org/10.1038/s41467-023-41975-3) - 7.6 ms at 440 Hz sampling, HEK293A cells, optical response to a single AP-like command waveform (2-ms FWHM), whole-cell voltage clamp, in vitro, 2P, 22°C — [Liu 2022, Fig. 2F](https://doi.org/10.1016/j.cell.2022.07.013) #### Brightness comparisons - 1.11× the brightness of ASAP3 — [Liu 2022, Fig. 2I](https://doi.org/10.1016/j.cell.2022.07.013) - 1× the brightness of ASAP1 — [Chamberland 2017, Fig. 1—figure supplement 2A](https://doi.org/10.7554/eLife.25690) - 0.45454545454545453× the brightness of JEDI-1P — [Lu 2023, Fig. 2h](https://doi.org/10.1038/s41467-023-41975-3) - 0.6666666666666666× the brightness of JEDI-2P — [Liu 2022, Fig. 2I](https://doi.org/10.1016/j.cell.2022.07.013) #### Photobleaching - curve only (did not reach 75% within the measured window) at 46 mW/mm², 1P — [Lu 2023, Fig. S4](https://doi.org/10.1038/s41467-023-41975-3) - t50% = 3 s at 15 mW/mm², 1P — [Liu 2022, Fig. S4G](https://doi.org/10.1016/j.cell.2022.07.013) - t75% = 50 s at 11 mW/mm², 1P — [Chamberland 2017, Fig. 1—figure supplement 3A](https://doi.org/10.7554/eLife.25690) - t75% = 47.7 s at 24 mW/mm², 1P — [Chamberland 2017, Fig. 2—figure supplement 3B](https://doi.org/10.7554/eLife.25690) - t75% = 20.4 s at 6.4 mW at objective back aperture (2P, 920 nm), 2P — [Chamberland 2017, Fig. 1—figure supplement 4A](https://doi.org/10.7554/eLife.25690) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 18%; -90 mV: 13%; -80 mV: 6%; -70 mV: 0%; -60 mV: -6%; -50 mV: -11%; -40 mV: -17%; -30 mV: -21%; -20 mV: -25%; -10 mV: -28%; 0 mV: -32%; 10 mV: -34%; 20 mV: -37%; 30 mV: -39%; 40 mV: -40%; 50 mV: -42% — [Chamberland 2017, Fig. 1C](https://doi.org/10.7554/eLife.25690) ### Research papers using ASAP2s (13) - [Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators](https://doi.org/10.7554/eLife.25690) — Chamberland S, Yang HH, et al., eLife 2017 (HEK293A cells; rat hippocampal neurons; Drosophila L2 neurons; mouse hippocampal slice cultures, in vitro/in vivo) - [In Vitro Testing of Voltage Indicators: Archon1, ArcLightD, ASAP1, ASAP2s, ASAP3b, Bongwoori-Pos6, BeRST1, FlicR1, and Chi-VSFP-Butterfly](https://doi.org/10.1523/ENEURO.0060-20.2020) — Milosevic MM, et al., eNeuro 2020 (Mouse, cortex; HEK293 cells, in vitro) - [Ultrafast two-photon imaging of a high-gain voltage indicator in awake behaving mice](https://doi.org/10.1016/j.cell.2019.11.004) — Villette V, et al., Cell 2019 (Rat, hippocampal neurons; HEK293A cells; mouse, cerebellar slices, in vitro) - [Imaging of Evoked Cortical Depolarizations Using Either ASAP2s, or chi-VSFP, or Di-4-Anepps, or Autofluorescence Optical Signals](https://doi.org/10.31083/j.jin2206160) — Milicevic KD, et al., Journal of Integrative Neuroscience 2023 (Mouse, cortex; ASAP2s-transgenic brain slices, ex vivo) - [CaMKII Measures the Passage of Time to Coordinate Behavior and Motivational State](https://doi.org/10.1016/j.neuron.2019.10.018) — Thornquist SC, et al., Neuron 2019 (Drosophila, abdominal ganglion neurons, ex vivo) - [Biochemical evidence accumulates across neurons to drive a network-level eruption](https://doi.org/10.1016/j.molcel.2020.12.029) — Thornquist SC, et al., Molecular Cell 2021 (Drosophila, Corazonin neurons, ex vivo) - [Drosophila TRPγ is required in neuroendocrine cells for post-ingestive food selection](https://doi.org/10.7554/eLife.56726) — Dhakal S, et al., eLife 2022 (Drosophila, DH44 neuroendocrine cells, in vivo) - [Triclosan disrupts immune cell function by depressing Ca2+ influx following acidification of the cytoplasm](https://doi.org/10.1016/j.taap.2020.115205) — Sangroula S, et al., Toxicology and Applied Pharmacology 2020 (RBL mast cells, in vitro) - [Real-time detection of changes in yeast plasma membrane potential using genetically encoded voltage indicator proteins](https://doi.org/10.1093/femsyr/foaa041) — Limapichat W, et al., FEMS Yeast Research 2020 (Saccharomyces cerevisiae, in vitro) - [A dark quencher genetically encodable voltage indicator (dqGEVI) exhibits high fidelity and speed](https://doi.org/10.1073/pnas.2020235118) — Alich TC, et al., Proceedings of the National Academy of Sciences 2021 (HEK293T cells; rat hippocampal neurons, in vitro) - [Sustained deep-tissue voltage recording using a fast indicator evolved for two-photon microscopy](https://doi.org/10.1016/j.cell.2022.07.013) — Liu Z, Lu X, et al., Cell 2022 (HEK293A cells; mouse hippocampal neurons, in vitro) - [Widefield imaging of rapid pan-cortical voltage dynamics with an indicator evolved for one-photon microscopy](https://doi.org/10.1038/s41467-023-41975-3) — Lu X, Wang Y, Liu Z, et al., Nature Communications 2023 (HEK293A cells; HEK293-Kir2.1 cells; rat cortical and hippocampal neurons, in vitro) - [Physiological features of parvalbumin-expressing GABAergic interneurons contributing to high-frequency oscillations in the cerebral cortex](https://doi.org/10.1016/j.crneur.2023.100121) — Milicevic KD, et al., Current Research in Neurobiology 2023 (Mouse, cortex; PV-ASAP2s transgenic brain slices, ex vivo) ## ASAP3 3rd-gen ASAP sensor with large fluorescence modulation and fast kinetics. - Category: VSD-cpGFP GEVI - Published: 2019-12-12 — [Cell 2019](https://doi.org/10.1016/j.cell.2019.11.004) - Derived from: [ASAP2s](https://gevibench.org/gevi/asap2s) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 490 nm, emission peak 509 nm (ASAP3) - Two-photon compatible: yes - Plasmid: [Addgene #132331](https://www.addgene.org/132331/) - Tags: cpGFP, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.45× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 6.8 / 11 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -51% (median of 5 measurements: −49.3%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.68% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 18% (median of 7 measurements: 13.3%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 5.7 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 52 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 27 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.7 ms, τ_off 6.72 ms at 32-35°C — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - τ_on 13.23 ms, τ_off 3.58 ms at 37°C — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) - τ_on 12.12 ms, τ_off 32.34 ms at 22-23°C — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - τ_on 4.49 ms, τ_off 21.54 ms at 32-35°C — [Liu 2022, Table S2](https://doi.org/10.1016/j.cell.2022.07.013) - τ_on 8.73 ms, τ_off 25.85 ms at 21-23°C — [Liu 2022, Table S2](https://doi.org/10.1016/j.cell.2022.07.013) - τ_on 9.11 ms, τ_off 18.8 ms at 23°C — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per 100 mV - -51%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - -49.3%, 1P — [Milosevic 2020, Fig. 2D](https://doi.org/10.1523/ENEURO.0060-20.2020) - -51%, 1P — [Rühl 2026, Table S1](https://doi.org/10.64898/2026.02.10.701308) - -43.5%, 1P — [Lu 2023, Fig. 2c](https://doi.org/10.1038/s41467-023-41975-3) - -47%, 1P — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per mV (subthreshold) - 0.46%/mV — [Villette 2019, Fig. S5E](https://doi.org/10.1016/j.cell.2019.11.004) - 0.9%/mV — [Hao 2024, Fig. S1C](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per action potential - 18%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 10.2%, 1P — [Evans 2023, Fig. 3c](https://doi.org/10.1038/s41592-023-01913-z) - 16.5%, 1P — [Lu 2023, Fig. 2n](https://doi.org/10.1038/s41467-023-41975-3) - 10.2%, 1P — [Piatkevich 2019, Ext. Fig. 5c](https://doi.org/10.1038/s41586-019-1641-1) - 17%, 2P — [Villette 2019, Fig. 3C](https://doi.org/10.1016/j.cell.2019.11.004) - 8.3%, 2P — [Villette 2019, Fig. 3E](https://doi.org/10.1016/j.cell.2019.11.004) - 37.3%, 2P — [Villette 2019, Fig. 3H](https://doi.org/10.1016/j.cell.2019.11.004) #### AP width (FWHM) - 5.8 ms at 987 Hz sampling, HEK293A cells, optical response to a single AP-like command waveform, whole-cell voltage clamp, 1P, 25°C — [Lu 2023, Fig. 2f](https://doi.org/10.1038/s41467-023-41975-3) - 12.7 ms at undefined Hz sampling, Cultured rat hippocampal neurons, optical response to current-evoked single APs, current clamp, room temperature, 1P, 25°C — [Villette 2019, Fig. 2F](https://doi.org/10.1016/j.cell.2019.11.004) - 3.4 ms at 3750 Hz sampling, Mouse, cortex, in vivo (ASAP3), 2P — [Villette 2024, Fig. 3f](https://doi.org/10.1101/2024.11.15.623698) - 5.6 ms at 1000 Hz sampling, HEK293A cells, optical response to a single AP-like command waveform (2-ms FWHM, +30 mV peak), whole-cell voltage clamp, 1P, 25°C — [Liu 2022, Fig. S4F](https://doi.org/10.1016/j.cell.2022.07.013) #### Brightness comparisons - 0.446× the brightness of EGFP — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 0.682× the brightness of ArcLight — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 197× the brightness of Archon1 — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 556× the brightness of QuasAr2 — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 0.167× the brightness of Ace2N-mNeon — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 0.87× the brightness of ASAP2s — [Lu 2023, Fig. 2h](https://doi.org/10.1038/s41467-023-41975-3) - 556× the brightness of paQuasAr3 — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 1.0638297872340425× the brightness of ASAP1 — [Nair 2025, Fig. 2C](https://doi.org/10.1021/acschemneuro.5c00670) - 2.2381378692927485× the brightness of ASAP4b — [Evans 2023, Ext. Fig. 3d](https://doi.org/10.1038/s41592-023-01913-z) - 2.7624309392265194× the brightness of ASAP4e — [Evans 2023, Ext. Fig. 3d](https://doi.org/10.1038/s41592-023-01913-z) - 1× the brightness of ASAP5 — [Hao 2024, Fig. 1G](https://doi.org/10.1016/j.neuron.2024.08.019) - 0.4098360655737705× the brightness of JEDI-1P — [Lu 2023, Fig. 2h](https://doi.org/10.1038/s41467-023-41975-3) - 0.5847953216374269× the brightness of JEDI-1P — [Nair 2025, Fig. 2C](https://doi.org/10.1021/acschemneuro.5c00670) - 0.5988023952095809× the brightness of JEDI-2P — [Liu 2022, Fig. 2I](https://doi.org/10.1016/j.cell.2022.07.013) - 0.5592841163310962× the brightness of rEstus-NI — [Nair 2025, Fig. 2C](https://doi.org/10.1021/acschemneuro.5c00670) - 0.48309178743961356× the brightness of rEstus — [Rühl 2024, Table 1](https://doi.org/10.1002/advs.202307938) - 0.5847953216374269× the brightness of rEstus — [Nair 2025, Table S1](https://doi.org/10.1021/acschemneuro.5c00670) - 0.9276437847866419× the brightness of rEstus2s — [Rühl 2026, Table S1](https://doi.org/10.64898/2026.02.10.701308) #### Photobleaching - t75% = 2.5 s at 920 nm, 20 mW post-objective (ULoVE pattern 3), 2P — [Villette 2019, Fig. 4D](https://doi.org/10.1016/j.cell.2019.11.004) - t50% = 295 s (extrapolated) at 46 mW/mm², 1P — [Lu 2023, Fig. S4](https://doi.org/10.1038/s41467-023-41975-3) - t75% = 95 s (extrapolated) at 100 mW/mm², 1P — [Evans 2023, Fig. 2b](https://doi.org/10.1038/s41592-023-01913-z) - t50% = 59 s, 1P — [Liu 2022, Fig. S4G](https://doi.org/10.1016/j.cell.2022.07.013) - t75% = 95 s at 25 mW/mm² (475 nm), 1P — [Piatkevich 2019, Ext. Fig. 5e](https://doi.org/10.1038/s41586-019-1641-1) - t75% = 886 s at ~10 µW/mm² (445 nm CW, in vivo), 1P — [Hao 2026, Ext. Fig. 3a](https://doi.org/10.64898/2026.05.27.728040) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -110 mV: 45%; -90 mV: 23%; -70 mV: 0%; -50 mV: -20%; -30 mV: -35%; -10 mV: -43%; 10 mV: -49%; 30 mV: -51% — [Villette 2019, Fig. 2A](https://doi.org/10.1016/j.cell.2019.11.004) ### Research papers using ASAP3 (27) - [Ultrafast Two-Photon Imaging of a High-Gain Voltage Indicator in Awake Behaving Mice](https://doi.org/10.1016/j.cell.2019.11.004) — Villette V, Chavarha M, et al., Cell 2019 (Mouse, visual cortex L2/3, in vivo; Drosophila, olfactory projection neurons, in vivo; HEK293 cells, in vitro) - [Population imaging of neural activity in awake behaving mice](https://doi.org/10.1038/s41586-019-1641-1) — Piatkevich KD, Bensussen S, Tseng HA, et al., Nature 2019 (Mouse, cortex L2/3 brain slices (ASAP3-Kv photostability); in vivo) - [Two-Photon Voltage Imaging of Spontaneous Activity from Multiple Neurons Reveals Network Activity in Brain Tissue](https://doi.org/10.1016/j.isci.2020.101363) — Li B, et al., iScience 2020 (Mouse, somatosensory cortex L2/3; acute slices, in vitro) - [In Vitro Testing of Voltage Indicators: Archon1, ArcLightD, ASAP1, ASAP2s, ASAP3b, Bongwoori-Pos6, BeRST1, FlicR1, and Chi-VSFP-Butterfly](https://doi.org/10.1523/ENEURO.0060-20.2020) — Milosevic MM, et al., eNeuro 2020 (Mouse, cortex; HEK293 cells, in vitro) - [A red fluorescent protein with improved monomericity enables ratiometric voltage imaging with ASAP3](https://doi.org/10.1038/s41598-022-07313-1) — Kim BB, et al., Scientific Reports 2022 (Rat, hippocampal neurons; human iPSC-derived cardiomyocytes; HEK293 cells, in vitro) - [Sustained deep-tissue voltage recording using a fast indicator evolved for two-photon microscopy](https://doi.org/10.1016/j.cell.2022.07.013) — Liu Z, et al., Cell 2022 (Drosophila, visual interneurons, in vivo; mouse, retina, ex vivo; mouse, visual cortex L2/3 and L5, in vivo) - [Electrical signals in the ER are cell type and stimulus specific with extreme spatial compartmentalization in neurons](https://doi.org/10.1016/j.celrep.2022.111943) — Campbell EP, et al., Cell Reports 2023 (Rat, hippocampal neurons; HEK293T cells, in vitro) - [High-speed low-light in vivo two-photon voltage imaging of large neuronal populations](https://doi.org/10.1038/s41592-023-01820-3) — Platisa J, et al., Nature Methods 2023 (Mouse, somatosensory cortex L2/3, in vivo; acute slices, in vitro) - [A positively tuned voltage indicator for extended electrical recordings in the brain](https://doi.org/10.1038/s41592-023-01913-z) — Evans SW, et al., Nature Methods 2023 (Mouse, hippocampus, cortex, in vivo; Drosophila, visual interneurons, in vivo; rat, hippocampal neurons, in vitro) - [Widefield imaging of rapid pan-cortical voltage dynamics with an indicator evolved for one-photon microscopy](https://doi.org/10.1038/s41467-023-41975-3) — Lu X, Wang Y, Liu Z, Gou Y, Jaeger D, St-Pierre F, Nature Communications 2023 (HEK293A cells, in vitro (ASAP3 benchmarked against JEDI-1P for response amplitude, spike-waveform width and photostability); rat hippocampal neurons, in vitro (ASAP3-Kv single-AP responses)) - [Dendritic mGluR2 and perisomatic Kv3 signaling regulate dendritic computation of mouse starburst amacrine cells](https://doi.org/10.1038/s41467-024-46234-7) — Ledesma HA, et al., Nature Communications 2024 (Mouse, retina, starburst amacrine cells, ex vivo) - [Two-dimensional electro-optical multiphoton microscopy](https://doi.org/10.1117/1.NPh.11.2.025005) — Farinella DM, et al., Neurophotonics 2024 (Mouse, visual cortex L2/3, in vivo) - [A novel rhodopsin-based voltage indicator for simultaneous two-photon optical recording with GCaMP in vivo](https://doi.org/10.1101/2024.11.15.623698) — Villette V, Yang S, Valenti R, Macklin JJ, Bradley J, Mathieu B, Lombardini A, Podgorski K, Dieudonné S, Schreiter ER, Abdelfattah AS, bioRxiv 2024 (Mouse, cortex and cerebellum, in vivo (ASAP3 spike amplitude / spike FWHM / photon flux cross-plotted against 2Photron-ST552 and JEDI-2P-Kv)) - [Cl⁻-dependent amplification of excitatory synaptic potentials at distal dendrites revealed by voltage imaging](https://doi.org/10.1126/sciadv.adj2547) — Higashi R, et al., Science Advances 2024 (Mouse, hippocampal neurons; acute slices, in vitro) - [A fast and responsive voltage indicator with enhanced sensitivity for unitary synaptic events](https://doi.org/10.1016/j.neuron.2024.08.019) — Hao YA, et al., Neuron 2024 (Mouse, motor cortex, barrel cortex, in vivo; Drosophila, visual interneurons, in vivo; rat, hippocampal neurons, in vitro) - [Volumetric voltage imaging of neuronal populations in the mouse brain by confocal light-field microscopy](https://doi.org/10.1038/s41592-024-02458-5) — Bai L, et al., Nature Methods 2024 (Mouse, cortex, in vivo) - [Development and Application of a Mitochondrial Genetically Encoded Voltage Indicator in Narcosis](https://doi.org/10.1007/s12264-024-01235-w) — Yang RZ, et al., Neuroscience Bulletin 2024 (Mouse, motor cortex, in vivo; cardiomyocytes; HEK293T cells, in vitro) - [An Ultrasensitive Genetically Encoded Voltage Indicator Uncovers the Electrical Activity of Non-Excitable Cells](https://doi.org/10.1002/advs.202307938) — Rühl P, et al., Advanced Science 2024 (Human cell lines, HEK293T, melanoma, breast cancer, in vitro) - [Functional architecture of intracellular oscillations in hippocampal dendrites](https://doi.org/10.1038/s41467-024-50546-z) — Liao Z, et al., Nature Communications 2024 (Mouse, hippocampus CA1, dendrites, in vivo) - [Absolute Membrane Potential Recording with ASAP-Type Genetically Encoded Voltage Indicators Using Fluorescence Lifetime Imaging](https://doi.org/10.1021/acschemneuro.5c00670) — Nair AG, et al., ACS Chemical Neuroscience 2025 (HEK293T cells; melanoma cells; breast cancer cells, in vitro) - [Voltage imaging reveals hippocampal inhibitory dynamics shaping pyramidal memory-encoding sequences](https://doi.org/10.1038/s41593-025-02016-y) — Taxidis J, et al., Nature Neuroscience 2025 (Mouse, hippocampus CA1, PV and SST interneurons, in vivo) - [An axonal brake on striatal dopamine output by cholinergic interneurons](https://doi.org/10.1038/s41593-025-01906-5) — Zhang YF, et al., Nature Neuroscience 2025 (Mouse, striatum, dopamine axons, in vivo; acute slices, ex vivo) - [Imaging high-frequency voltage dynamics in multiple neuron classes of behaving mammals](https://doi.org/10.1016/j.cell.2025.06.028) — Haziza S, et al., Cell 2025 (Mouse, hippocampus CA1/CA3, visual cortex, motor cortex, in vivo; freely moving and head-fixed) - [Neuronal activity induces myelin voltage changes that reflect action potential dependent myelin potassium buffering](https://doi.org/10.64898/2025.12.16.694668) — Labarchède M, et al., bioRxiv 2025 (Mouse, oligodendrocytes, myelin, in vivo) - [Sub-Millivolt Voltage Imaging Reveals Gap Junction-Mediated Bioelectric Contact Inhibition](https://doi.org/10.64898/2026.02.10.701308) — Rühl P, Hussein R, Reuter S, Frahnert K, Nair AG, Mrowka R, Schönherr R, Heinemann SH, bioRxiv 2026 (HEK293T cells, in vitro (ASAP3 benchmarked alongside rEstus2s)) - [Ultrasensitive voltage imaging reveals distinct electrical microdomains in neurons](https://doi.org/10.64898/2026.05.27.728040) — Hao YA, Jayne LL, Lee S, Dittrich MN, Zhang M, et al., bioRxiv 2026 (Mouse, cortex PV interneurons, in vivo (ASAP3 photostability vs ASAP7y); cultured neurons; HEK293 cells, in vitro) - [Movement-stabilized three-dimensional optical recordings of membrane potential changes and calcium dynamics in hippocampal CA1 dendrites](https://doi.org/10.1016/j.neuron.2026.01.004) — Gonzalez KC, et al., Neuron 2026 (Mouse, hippocampus CA1, dendrites and soma, in vivo) ## ASAP4b Bright-optimized ASAP4 variant with superior brightness and photostability for extended two-photon recordings. - Category: VSD-cpGFP GEVI - Published: 2023-07-06 — [Nature Methods 2023](https://doi.org/10.1038/s41592-023-01913-z) - Derived from: [ASAP3](https://gevibench.org/gevi/asap3) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 375 nm, emission peak 522 nm (ASAP4b) - Two-photon compatible: yes - Plasmid: [Addgene #201030](https://www.addgene.org/201030/) - Tags: cpGFP, Positive-going, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.20× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 5.6 / 7.0 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +180% (median of 2 measurements: +174%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.3% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 35% (median of 6 measurements: 28%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 8.7 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 59 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 5 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 17.66 ms, τ_off 22.85 ms at 22°C — [Evans 2023, Table S1](https://doi.org/10.1038/s41592-023-01913-z) - τ_on 5.56 ms, τ_off 7 ms at 37°C — [Evans 2023, Table S1](https://doi.org/10.1038/s41592-023-01913-z) #### ΔF/F per 100 mV - +180%, 1P — [Evans 2023, Table 1](https://doi.org/10.1038/s41592-023-01913-z) - +168%, 1P — [Lee 2024, Table S1](https://doi.org/10.1101/2024.06.21.599617) #### ΔF/F per action potential - 35%, 1P — [Evans 2023, Table 1](https://doi.org/10.1038/s41592-023-01913-z) - 30%, 1P — [Evans 2023, Ext. Fig. 5c](https://doi.org/10.1038/s41592-023-01913-z) - 31%, 1P — [Lee 2024, Table S1](https://doi.org/10.1101/2024.06.21.599617) - 13%, 1P — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) - 19%, 1P — [Evans 2023, Ext. Fig. 5a](https://doi.org/10.1038/s41592-023-01913-z) - 26%, 1P — [Evans 2023, Ext. Fig. 5a](https://doi.org/10.1038/s41592-023-01913-z) #### AP width (FWHM) - 7.4 ms at 1000 Hz sampling, HEK293A cells, whole-cell voltage clamp, hippocampal-neuron AP command waveform scaled to 2-ms FWHM (−70 → +30 mV), 1P, 22°C — [Evans 2023, Ext. Fig. 5a](https://doi.org/10.1038/s41592-023-01913-z) - 10 ms at 1000 Hz sampling, HEK293A cells, whole-cell voltage clamp, hippocampal-neuron AP command waveform scaled to 4-ms FWHM (−70 → +30 mV), 1P, 22°C — [Evans 2023, Ext. Fig. 5a](https://doi.org/10.1038/s41592-023-01913-z) #### Brightness comparisons - 0.4468× the brightness of ASAP3 — [Evans 2023, Ext. Fig. 3d](https://doi.org/10.1038/s41592-023-01913-z) #### Photobleaching - t75% = 59 s at 100 mW/mm², 1P — [Evans 2023, Fig. 2b](https://doi.org/10.1038/s41592-023-01913-z) - curve only (did not reach 75% within the measured window) at 888 mW/mm², 2P — [Evans 2023, Ext. Fig. 4b](https://doi.org/10.1038/s41592-023-01913-z) - t75% = 71 s at 960 mW/mm², 2P — [Evans 2023, Ext. Fig. 4c](https://doi.org/10.1038/s41592-023-01913-z) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: -24%; -100 mV: -17%; -80 mV: -10%; -70 mV: 0%; -60 mV: 15%; -40 mV: 34%; -20 mV: 66%; 0 mV: 96%; 30 mV: 168%; 50 mV: 201%; 70 mV: 222%; 90 mV: 235%; 120 mV: 246% — [Evans 2023, Fig. 1B](https://doi.org/10.1038/s41592-023-01913-z) ### Research papers using ASAP4b (5) - [A positively tuned voltage indicator for extended electrical recordings in the brain](https://doi.org/10.1038/s41592-023-01913-z) — Evans SW, Shi DQ, Chavarha M, et al., Nature Methods 2023 (HEK293A cells (voltage clamp), mouse hippocampus and striatum, in vivo (origin paper introducing ASAP4b)) - [Improving positively tuned voltage indicators for faster kinetics and higher contrast](https://doi.org/10.1101/2024.06.21.599617) — Lee S, Zhang G, Hao YA, et al., bioRxiv 2024 (HEK293A cells, voltage clamp and AP-waveform characterization of ASAP4b) - [Positive-going hybrid indicators for voltage imaging in excitable cells and tissues](https://doi.org/10.1126/sciadv.ads1807) — Liu S, et al., Science Advances 2025 (Cultured rat hippocampal neurons, ASAP4b used as a green positive-going reference (484 Hz, 1P)) - [Voltage imaging reveals hippocampal inhibitory dynamics shaping pyramidal memory-encoding sequences](https://doi.org/10.1038/s41593-025-02016-y) — Taxidis J, et al., Nature Neuroscience 2025 (Mouse, dorsal CA1 hippocampus, SST+ interneurons, in vivo 1P widefield (AAV8-EF1α-DiO-ASAP4b-Kv, 2 mice; ASAP4e-Kv in 3 more, ASAP3-Kv in the main cohort)) - [Imaging sensory transmission and neuronal plasticity in primary sensory neurons with a positively tuned voltage indicator](https://doi.org/10.1038/s41467-025-61774-2) — Zhang Y, et al., Nature Communications 2025 (Mouse, L5 dorsal root ganglia, in vivo (the paper's sensor is named ASAP4.4-Kv; the text never says ASAP4b, and no ASAP4.4 appears in the ASAP4 paper - identity vs ASAP4b UNCONFIRMED)) ## ASAP4e Speed-optimized ASAP4 variant with fast kinetics and a large fluorescence increase per action potential. - Category: VSD-cpGFP GEVI - Published: 2023-07-06 — [Nature Methods 2023](https://doi.org/10.1038/s41592-023-01913-z) - Derived from: [ASAP3](https://gevibench.org/gevi/asap3) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 375 nm, emission peak 524 nm (ASAP4e) - Two-photon compatible: yes - Plasmid: [Addgene #201031](https://www.addgene.org/201031/) - Tags: cpGFP, Positive-going, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.17× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 6.3 / 5.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +210% (median of 3 measurements: +211%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.1% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 38% (median of 5 measurements: 33%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 5 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 6 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 18.29 ms, τ_off 15.6 ms at 22°C — [Evans 2023, Table S1](https://doi.org/10.1038/s41592-023-01913-z) - τ_on 4.55 ms, τ_off 4.71 ms at 37°C — [Evans 2023, Table S1](https://doi.org/10.1038/s41592-023-01913-z) - τ_on 8.14 ms, τ_off 6.7 ms at 33°C — [McDonald 2026, Table S1.4](https://doi.org/10.64898/2026.04.07.717088) #### ΔF/F per 100 mV - +210%, 1P — [Evans 2023, Table 1](https://doi.org/10.1038/s41592-023-01913-z) - +148%, 2P — [McDonald 2026, Fig. 1F](https://doi.org/10.64898/2026.04.07.717088) - +212%, 1P — [Lee 2024, Table S1](https://doi.org/10.1101/2024.06.21.599617) #### ΔF/F per mV (subthreshold) - 1.12%/mV, 2P (Cross-measured in the FORCE1s paper (McDonald et al. 2026). Subthreshold steady-state response to a 30-mV depolarization from −70 → −40 mV = 33.6 ± 6.4% (n = 5, whole-cell voltage clamp + 2P imaging at 33 °C, HEK293A; main text and Fig. 1E/Fig. S1.2C). Expressed as a slope: 33.6% / 30 mV ≈ 1.12 %/mV (cf. FORCE1s 87.4% → 2.91 %/mV, JEDI-2P 25.9% → 0.86 %/mV over the same step).) — [McDonald 2026, Fig. 1E](https://doi.org/10.64898/2026.04.07.717088) #### ΔF/F per action potential - 38%, 1P — [Evans 2023, Table 1](https://doi.org/10.1038/s41592-023-01913-z) - 23%, 1P — [Evans 2023, Ext. Fig. 5a](https://doi.org/10.1038/s41592-023-01913-z) - 41%, 1P — [Evans 2023, Ext. Fig. 5c](https://doi.org/10.1038/s41592-023-01913-z) - 33%, 1P — [Lee 2024, Table S1](https://doi.org/10.1101/2024.06.21.599617) - 32%, 1P — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) #### AP width (FWHM) - 5.8 ms at 400 Hz sampling, Mouse barrel cortex L2/3 pyramidal neurons, in vivo, whisker stimulation (ASAP4e-Kv), 2P, 37°C — [Lee 2024, Fig. 3d](https://doi.org/10.1101/2024.06.21.599617) - 4.2 ms at 721 Hz sampling, HEK293A cells, whole-cell voltage clamp, in vitro (2-ms FWHM command AP waveform), 2P, 33°C — [McDonald 2026, Fig. 1K](https://doi.org/10.64898/2026.04.07.717088) #### Brightness comparisons - 0.362× the brightness of ASAP3 — [Evans 2023, Ext. Fig. 3d](https://doi.org/10.1038/s41592-023-01913-z) - 0.5× the brightness of FORCE1s — [McDonald 2026, Fig. 1C](https://doi.org/10.64898/2026.04.07.717088) - 0.6666666666666666× the brightness of ASAP5 — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) - 1× the brightness of ASAP6c — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) - 0.03571428571428571× the brightness of pAce — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) - 0.2857142857142857× the brightness of Positron — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) #### Photobleaching - t75% = 104 s at 100 mW at sample plane (2P, 940 nm), 2P — [McDonald 2026, Fig. S1.2B](https://doi.org/10.64898/2026.04.07.717088) - curve only (did not reach 75% within the measured window) at 100 mW/mm², 1P — [Evans 2023, Fig. 2b](https://doi.org/10.1038/s41592-023-01913-z) - t75% = 141 s at 960 mW/mm² (2P galvanometric scanning, 5 min), 2P — [Evans 2023, Ext. Fig. 4c](https://doi.org/10.1038/s41592-023-01913-z) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: -13%; -100 mV: -9%; -80 mV: -3%; -70 mV: 0%; -60 mV: 6%; -40 mV: 22%; -20 mV: 55%; 0 mV: 98%; 30 mV: 210%; 50 mV: 300%; 70 mV: 360%; 90 mV: 410%; 120 mV: 460% — [Evans 2023, Fig. 1B](https://doi.org/10.1038/s41592-023-01913-z) ### Research papers using ASAP4e (6) - [A positively tuned voltage indicator for extended electrical recordings in the brain](https://doi.org/10.1038/s41592-023-01913-z) — Evans SW, Shi DQ, Chavarha M, et al., Nature Methods 2023 (HEK293A cells (voltage clamp), mouse hippocampus and cortex, in vivo (origin paper introducing ASAP4e)) - [Improving positively tuned voltage indicators for faster kinetics and higher contrast](https://doi.org/10.1101/2024.06.21.599617) — Lee S, Zhang G, Hao YA, et al., bioRxiv 2024 (HEK293A cells, voltage clamp and AP-waveform characterization of ASAP4e) - [A versatile, positive-going voltage indicator that enables accessible two-photon recordings in vivo](https://doi.org/10.64898/2026.04.07.717088) — McDonald AJ, Land MA, Yang S, et al., bioRxiv 2026 (HEK293A cells, ASAP4e benchmarked under 2P excitation against FORCE1s (kinetics, F-V, brightness, spike waveforms)) - [Voltage imaging reveals hippocampal inhibitory dynamics shaping pyramidal memory-encoding sequences](https://doi.org/10.1038/s41593-025-02016-y) — Taxidis J, et al., Nature Neuroscience 2025 (Mouse, hippocampus CA1, PV and SST interneurons, in vivo) - [Imaging sensory transmission and neuronal plasticity in primary sensory neurons with a positively tuned voltage indicator](https://doi.org/10.1038/s41467-025-61774-2) — Zhang Y, et al., Nature Communications 2025 (Mouse, dorsal root ganglia neurons, in vivo) - [High-speed neural imaging with multiplexed miniaturized two-photon microscopy](https://doi.org/10.1016/j.crmeth.2025.101221) — Zhang Z, Liu SJ, Mattison B, Muir J, Spurr N, Kim CK, Yang W, Cell Reports Methods 2025 (Mouse, primary visual cortex (V1), freely moving, in vivo; two-photon voltage imaging of ASAP4e at 400 Hz over a 380 x 150 um FOV at 140-280 um depth (M-MINI2P)) ## ASAP5 Optimized for detecting subthreshold activity, with the steepest F-V slope near resting potential. - Category: VSD-cpGFP GEVI - Published: 2024-09-20 — [Neuron 2024](https://doi.org/10.1016/j.neuron.2024.08.019) - Derived from: [ASAP3](https://gevibench.org/gevi/asap3) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 488 nm, emission peak 525 nm (ASAP5) - Two-photon compatible: yes - Plasmid: [Addgene #225709](https://www.addgene.org/225709/) - Tags: cpGFP, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.31× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.0 / 2.6 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -57% (median of 2 measurements: −57%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.3% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 34% (median of 2 measurements: 34%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 17 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 11 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.97 ms, τ_off 2.62 ms at 37°C — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) - τ_on 6.02 ms, τ_off 17.2 ms at 23°C — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per 100 mV - -57%, 1P — [Hao 2024, Fig. 1D](https://doi.org/10.1016/j.neuron.2024.08.019) - -35.2%, 2P — [Land 2026, Ext. Fig. 1b](https://doi.org/10.1038/s41592-026-03043-8) #### ΔF/F per mV (subthreshold) - 1.3%/mV — [Hao 2024, Fig. S1C](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per action potential - 34%, 1P — [Hao 2024, Fig. 1F](https://doi.org/10.1016/j.neuron.2024.08.019) - 13%, 2P — [Hao 2026, Fig. 2k](https://doi.org/10.64898/2026.05.27.728040) #### AP width (FWHM) - 1.3 ms at 7142 Hz sampling, Mouse, visual cortex L2/3 pyramidal neurons, awake behaving, in vivo, soma-targeted ASAP5-Kv (ULoVE 2P), 2P, 37°C — [Hao 2024, Fig. S4E](https://doi.org/10.1016/j.neuron.2024.08.019) - 6.8 ms at undefined Hz sampling, Rat, cultured cortical neurons, current-evoked APs, in vitro — [Hao 2026, Fig. 1c](https://doi.org/10.64898/2026.05.27.728040) #### Brightness comparisons - 1× the brightness of ASAP3 — [Hao 2024, Fig. 1G](https://doi.org/10.1016/j.neuron.2024.08.019) - 1.5× the brightness of ASAP4e — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) - 0.78125× the brightness of ASAP7y — [Hao 2026, Fig. 2l](https://doi.org/10.64898/2026.05.27.728040) - 0.6896551724137931× the brightness of JEDI-2P — [Land 2026, Ext. Fig. 1c](https://doi.org/10.1038/s41592-026-03043-8) - 0.8× the brightness of JEDI-3hyp — [Land 2026, Ext. Fig. 1c](https://doi.org/10.1038/s41592-026-03043-8) - 0.7194244604316548× the brightness of JEDI-3sub — [Land 2026, Ext. Fig. 1c](https://doi.org/10.1038/s41592-026-03043-8) #### Photobleaching - t75% = 37.6 s (extrapolated) at 46 mW/mm², 1P — [Hao 2024, Fig. S5E](https://doi.org/10.1016/j.neuron.2024.08.019) - curve only (did not reach 75% within the measured window) at 16 mW at 940 nm (2P power-only), 2P — [Hao 2026, Fig. 2g](https://doi.org/10.64898/2026.05.27.728040) - curve only (did not reach 75% within the measured window) at 25 mW at 920 nm (2P power-only), 2P — [Hao 2024, Fig. 3A](https://doi.org/10.1016/j.neuron.2024.08.019) - t75% = 970 s at 30-160 mW at 925 nm (2P power-only), 2P — [Hao 2024, Fig. S4A](https://doi.org/10.1016/j.neuron.2024.08.019) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 57%; -100 mV: 38%; -80 mV: 14%; -70 mV: 0%; -60 mV: -13%; -40 mV: -33%; -20 mV: -45%; 0 mV: -52%; 30 mV: -57%; 50 mV: -59%; 80 mV: -60% — [Hao 2024, Fig. 1D](https://doi.org/10.1016/j.neuron.2024.08.019) ### Research papers using ASAP5 (11) - [A fast and responsive voltage indicator with enhanced sensitivity for unitary synaptic events](https://doi.org/10.1016/j.neuron.2024.08.019) — Hao YA, Lee S, Roth RH, Natale S, Gomez L, Taxidis J, et al., Neuron 2024 (HEK293A cells; cultured rat/human neurons; mouse motor/barrel cortex and hippocampus; Drosophila Mi1 and TPN-II; zebrafish tectum; in vitro and in vivo) - [Ultrasensitive voltage imaging reveals distinct electrical microdomains in neurons](https://doi.org/10.64898/2026.05.27.728040) — Hao YA, Jayne LL, Lee S, Dittrich MN, Zhang M, et al., bioRxiv 2026 (Drosophila Mi1 and TPN-II neurons, in vivo; cultured cortical neurons; ASAP5 characterized alongside ASAP7y) - [Deep two-photon voltage imaging with adaptive excitation](https://doi.org/10.21203/rs.3.rs-5434919/v1) — Zhao S, Hebert E, Gruzdeva A, Mahishi D, Takahashi H, Lee S, Hao YA, Lin MZ, Yapici N, Xu C, Research Square 2024 (Mouse, visual cortex, in vivo) - [A deep learning framework for automated and generalized synaptic event analysis](https://doi.org/10.7554/eLife.98485) — O'Neill PS, Baccino-Calace M, Rupprecht P, Lee S, Hao YA, Lin MZ, Friedrich RW, Mueller M, Delvendahl I, eLife 2025 (Rat, hippocampal neurons, in vitro) - [Selective life-long suppression of an odor processing channel in response to critical period experience](https://doi.org/10.1101/2025.07.18.665601) — Leier HC, et al., bioRxiv 2025 (Drosophila, olfactory sensory neurons, in vivo) - [Retroreflective beam multiplexing enables high-throughput two-photon voltage imaging in vivo](https://doi.org/10.64898/2025.12.09.693349) — Liu Z, Han M, Chen Y, Downs NP, Wu J, bioRxiv 2025 (Mouse, visual cortex, hippocampus, in vivo) - [Kilohertz-rate two-photon voltage imaging of population dynamics in vivo](https://doi.org/10.64898/2025.12.29.696942) — Zhang M, et al., bioRxiv 2026 (Mouse, cortical neurons, in vivo) - [Designer indicators for two-photon recording of subthreshold voltage dynamics](https://doi.org/10.1038/s41592-026-03043-8) — Land MA, Galdamez M, Villette V, Zhu J, Lu X, Marosi M, et al., Nature Methods 2026 (HEK293 cells, in vitro; Mouse, visual cortex L2/3, in vivo) - [Highly attenuated dendritic propagation of isolated synaptic potentials in vivo](https://doi.org/10.1126/sciadv.adz4123) — Cornejo VH, Bouazza-Arostegui B, Alejandre-Garcia T, Hao YA, Lee S, Lin MZ, Yuste R, Science Advances 2026 (Mouse, somatosensory cortex L2/3 pyramidal dendrites and spines, in vivo (two-photon voltage imaging with ASAP5 targeted by the PSD95.FingR nanobody, with simultaneous somatic whole-cell patch clamp)) - [Structure-guided, physics-aware reconstruction expands scan-limited multiphoton imaging](https://doi.org/10.64898/2026.04.20.719672) — Liu S, et al., bioRxiv 2026 (Mouse, somatosensory cortex, in vivo (AAV-CaMKIIα-ASAP5-Kv two-photon voltage imaging)) - [Voltage imaging of neurons distributed across entire brains of larval zebrafish](https://doi.org/10.1038/s41592-026-03179-7) — Wang Z, et al., Nature Methods 2026 (Zebrafish larva, whole brain, in vivo (sparse transient ASAP5-Kv expression used to verify that spikes resolved at 1,000 Hz survive downsampling to 200 Hz; ASAP5-Kv kinetics also used in the sampling-rate simulations)) ## ASAP6c Contrast-optimized descendant of ASAP4b with the largest per-spike fluorescence increase and signal-to-noise of the ASAP lineage for one- and two-photon spike detection in vivo. - Category: VSD-cpGFP GEVI - Published: 2026-05-04 — [bioRxiv 2026](https://doi.org/10.1101/2024.06.21.599617) - Derived from: [ASAP4b](https://gevibench.org/gevi/asap4b) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 497 nm, emission peak 520 nm (ASAP6c) - Two-photon compatible: yes - Tags: cpGFP, Positive-going, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.11× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.9 / 4.4 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +222% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.1% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 70% (median of 3 measurements: 84%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 5.3 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 3.93 ms, τ_off 4.41 ms at 25°C — [Lee 2024, Table S3](https://doi.org/10.1101/2024.06.21.599617) #### ΔF/F per 100 mV - +222%, 1P — [Lee 2024, Table S2](https://doi.org/10.1101/2024.06.21.599617) #### ΔF/F per action potential - 70%, 1P — [Lee 2024, Table S2](https://doi.org/10.1101/2024.06.21.599617) - 98%, 1P — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) - 83%, 2P — [Lee 2024, Fig. 3d](https://doi.org/10.1101/2024.06.21.599617) #### AP width (FWHM) - 5.7 ms at 400 Hz sampling, Mouse barrel cortex L2/3 pyramidal neurons, in vivo, whisker stimulation (ASAP6c-Kv), 2P, 37°C — [Lee 2024, Fig. 3d](https://doi.org/10.1101/2024.06.21.599617) - 4.9 ms at 800 Hz sampling, HEK293A cells, whole-cell voltage clamp, in vitro (simulated 2-ms-FWHM, 100-mV command AP waveform), 1P, 25°C — [Lee 2024, Fig. 1d](https://doi.org/10.1101/2024.06.21.599617) #### Brightness comparisons - 1× the brightness of ASAP4e — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -170 mV: -41%; -150 mV: -39%; -120 mV: -27%; -90 mV: -18%; -70 mV: 0%; -50 mV: 24%; -30 mV: 60%; -10 mV: 95%; 5 mV: 136%; 30 mV: 215%; 50 mV: 279%; 80 mV: 325% — [Lee 2024, Fig. 1c](https://doi.org/10.1101/2024.06.21.599617) ### Research papers using ASAP6c (1) - [Improving positively tuned voltage indicators for faster kinetics and higher contrast](https://doi.org/10.1101/2024.06.21.599617) — Lee S, Zhang G, Hao YA, Roth RH, Sun Y, Dong C, Zhu J, Gomez LC, Natan RG, Jiang D, Liu LX, Testa-Silva G, Hiramoto A, Roska B, Feldman D, Ji N, Clandinin TR, Giocomo L, Ding J, Lin MZ, bioRxiv 2026 (HEK293A cells, rat hippocampal neurons in vitro, mouse CA1 hippocampus in vivo (1P and 2P), mouse motor cortex in vivo (1P), mouse barrel cortex in vivo (2P), mouse visual cortex in vivo (FACED 2P), Htr3a+ interneurons in vivo) ## ASAP7y Red-shifted ASAP5 variant optimized for ultrasensitive subthreshold voltage imaging, with a steep response near resting potential and excitation compatibility extending to high-power 1030-nm fiber lasers. - Category: VSD-cpGFP GEVI - Published: 2026-05-31 — [bioRxiv 2026](https://doi.org/10.64898/2026.05.27.728040) - Derived from: [ASAP5](https://gevibench.org/gevi/asap5) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 510 nm, emission peak 525 nm (ASAP7y) - Two-photon compatible: yes - Tags: cpGFP, Green, Two-photon, Subthreshold ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.34× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 0.90 / 2.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -80% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 2% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 62% (median of 3 measurements: 62%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 10 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 1.3 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 3 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 0.9 ms, τ_off 2.7 ms at 37°C — [Hao 2026, Ext. Fig. 1b](https://doi.org/10.64898/2026.05.27.728040) - τ_on 3 ms, τ_off 10.7 ms at 25°C — [Hao 2026, Ext. Fig. 1b](https://doi.org/10.64898/2026.05.27.728040) #### ΔF/F per 100 mV - -80%, 1P — [Hao 2026, Fig. 1b](https://doi.org/10.64898/2026.05.27.728040) #### ΔF/F per mV (subthreshold) - 2.7%/mV (Voltage-fluorescence conversion ratio around resting membrane potential in HEK293 cells (2-fold higher than ASAP5 at 1.3%/mV)) — [Hao 2026, Fig. 1b](https://doi.org/10.64898/2026.05.27.728040) - 1.9%/mV (In vivo whole-cell patch-clamp near resting membrane voltage in mouse visual cortex) — [Hao 2026, Fig. 1f](https://doi.org/10.64898/2026.05.27.728040) - 2%/mV (Subthreshold -ΔF/F₋₇₀ per mV measured in cultured rat cortical neurons during current-injection-evoked plateau potentials (n = 7 cells; P < 0.0001 vs ASAP5). Read off the Fig. 1d bar chart, whose y-axis is literally 'Subthreshold -ΔF/F₋₇₀ per mV (%)': ASAP7y bar ≈ 2.0%/mV vs ASAP5 ≈ 0.78%/mV, consistent with the main text's 'responses to subthreshold activities were 140% larger'. This is the neuronal counterpart of the 2.7%/mV HEK293 F-V slope (Fig. 1b) and the 1.9%/mV in-vivo value (Fig. 1f). (The Ext. Fig. 1c commanded 3-mV EPSP gives the same figure independently: -6% ΔF/F0 ÷ 3 mV = 2.0%/mV in HEK293 at 37°C.)) — [Hao 2026, Fig. 1d](https://doi.org/10.64898/2026.05.27.728040) #### ΔF/F per action potential - 62%, 1P — [Hao 2026, Ext. Fig. 1c](https://doi.org/10.64898/2026.05.27.728040) - 24%, 2P — [Hao 2026, Fig. 2k](https://doi.org/10.64898/2026.05.27.728040) - 46% — [Hao 2026, Fig. 1c](https://doi.org/10.64898/2026.05.27.728040) #### AP width (FWHM) - 10.3 ms at undefined Hz sampling, Rat, cultured cortical neurons, current-evoked APs, in vitro — [Hao 2026, Fig. 1c](https://doi.org/10.64898/2026.05.27.728040) #### Brightness comparisons - 1.28× the brightness of ASAP5 — [Hao 2026, Fig. 2l](https://doi.org/10.64898/2026.05.27.728040) #### Photobleaching - t75% = 12600 s (extrapolated) at ~10 µW/mm² (445 nm, in vivo), 1P — [Hao 2026, Ext. Fig. 3a](https://doi.org/10.64898/2026.05.27.728040) - curve only (did not reach 75% within the measured window) at 16 mW at 940 nm (2P power-only), 2P — [Hao 2026, Fig. 2g](https://doi.org/10.64898/2026.05.27.728040) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 100%; -100 mV: 78%; -80 mV: 25%; -70 mV: 0%; -60 mV: -30%; -40 mV: -60%; -20 mV: -75%; 0 mV: -80%; 30 mV: -85%; 80 mV: -90% — [Hao 2026, Fig. 1b](https://doi.org/10.64898/2026.05.27.728040) ### Research papers using ASAP7y (3) - [Ultrasensitive voltage imaging reveals distinct electrical microdomains in neurons](https://doi.org/10.64898/2026.05.27.728040) — Hao YA, Jayne LL, Lee S, Dittrich MN, Zhang M, Haziza S, Bendifallah I, Sims RR, Bouazza-Arostegui B, White AD, Kochalka J, Wang Y, Seyedmohadesin M, Negrean A, Li Z, Chiu C, Podgorski K, Ding JB, Deisseroth K, Yuste R, Emiliani V, Schnitzer MJ, Lin MZ, Clandinin TR, bioRxiv 2026 (HEK293 cells, in vitro; rat cortical neurons, in vitro; mouse organotypic hippocampal slices; mouse visual cortex, in vivo; Drosophila visual system, in vivo) - [Intrinsic space-time couplings governing multi-scale cortical dynamics](https://doi.org/10.64898/2026.05.27.726038) — White AD, Wang Y, Kochalka J, Hao YA, Li C, Hernandez M, Andini N, Pyo KE, Wenderski W, Mitra A, Eshaghi Gharagoz B, Kadur C, Ganguli S, Clandinin TR, Lin MZ, Deisseroth K, bioRxiv 2026 (Mouse, dorsal cortex (cortex-wide voltage imaging), in vivo) - [Causal and directional elements of global brain dynamics](https://doi.org/10.64898/2026.05.27.726039) — Kochalka J, Mitra A, White AD, Wang Y, Sheng K, Hao YA, Kadur C, Ramakrishnan C, Hernandez M, Wenderski W, Po KE, Andini N, Clandinin TR, Lin MZ, Druckmann S, Deisseroth K, bioRxiv 2026 (Mouse, cortex-wide (excitatory and inhibitory neurons), in vivo) ## Bongwoori ArcLight-derived voltage indicator with an improved voltage-sensing domain. - Category: VSD-single FP - Published: 2015-01-07 — [Journal of Neuroscience 2015](https://doi.org/10.1523/JNEUROSCI.3008-14.2015) - Derived from: [ArcLight](https://gevibench.org/gevi/arclight) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 488 nm, emission peak 511 nm (Bongwoori) - Plasmid: [Addgene #63720](https://www.addgene.org/63720/) - Tags: pHluorin, Ci-VSP ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.19× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 14 / 11 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -13% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.05% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 3.7% (median of 2 measurements: 3.1%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 33 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 1.2 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 9 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 10 ms, τ_off 7 ms at 33°C — [Piao 2015, Table 2](https://doi.org/10.1523/JNEUROSCI.3008-14.2015) - τ_on 17 ms, τ_off 14 ms at 34°C — [Lee 2017, Table 2](https://doi.org/10.1038/s41598-017-08731-2) #### ΔF/F per 100 mV - -13%, 1P — [Lee 2017, Fig. 4B](https://doi.org/10.1038/s41598-017-08731-2) #### ΔF/F per action potential - 3.7%, 1P — [Lee 2017, Table 3](https://doi.org/10.1038/s41598-017-08731-2) - 2.5%, 1P — [Piao 2015, Discussion](https://doi.org/10.1523/JNEUROSCI.3008-14.2015) #### AP width (FWHM) - 33.1 ms at 500 Hz sampling, Mouse, cultured hippocampal neurons, in vitro, 1P — [Milosevic 2020, Fig. 1C](https://doi.org/10.1523/ENEURO.0060-20.2020) #### Brightness comparisons - 0.29× the brightness of ArcLight — [Lee 2017, Table 3](https://doi.org/10.1038/s41598-017-08731-2) - 0.5291005291005292× the brightness of Bongwoori-R3 — [Lee 2017, Table 3](https://doi.org/10.1038/s41598-017-08731-2) #### Photobleaching - t75% = 124 s at 1 mW/mm², 1P — [Lee 2017, Fig. S1](https://doi.org/10.1038/s41598-017-08731-2) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 1%; -70 mV: 0%; -20 mV: -4%; 30 mV: -13%; 80 mV: -19%; 130 mV: -19% — [Lee 2017, Fig. 4B](https://doi.org/10.1038/s41598-017-08731-2) ### Research papers using Bongwoori (9) - [Combinatorial mutagenesis of the voltage-sensing domain enables the optical resolution of action potentials firing at 60 Hz by a genetically encoded fluorescent sensor of membrane potential](https://doi.org/10.1523/JNEUROSCI.3008-14.2015) — Piao HH, et al., Journal of Neuroscience 2015 (HEK293 cells; cultured mouse hippocampal neurons, in vitro) - [Improving a genetically encoded voltage indicator by modifying the cytoplasmic charge composition](https://doi.org/10.1038/s41598-017-08731-2) — Lee S, et al., Scientific Reports 2017 (HEK293 cells; cultured mouse hippocampal neurons, in vitro) - [Optical consequences of a genetically-encoded voltage indicator with a pH sensitive fluorescent protein](https://doi.org/10.1016/j.neures.2018.10.006) — Kang BE, et al., Neuroscience Research 2019 (HEK293 cells; cultured hippocampal neurons, in vitro) - [Engineering photoactivatability in genetically encoded voltage and pH indicators](https://doi.org/10.3389/fncel.2019.00482) — Lee S, et al., Frontiers in Cellular Neuroscience 2019 (HEK293 cells, in vitro) - [In vitro testing of voltage indicators: Archon1, ArcLightD, ASAP1, ASAP2s, ASAP3b, Bongwoori-Pos6, BeRST1, FlicR1, and Chi-VSFP-Butterfly](https://doi.org/10.1523/ENEURO.0060-20.2020) — Milosevic MM, et al., eNeuro 2020 (Cultured hippocampal neurons; mouse brain slices, in vitro/ex vivo) - [Mechanism of ArcLight derived GEVIs involves electrostatic interactions that can affect proton wires](https://doi.org/10.1016/j.bpj.2021.03.009) — Kang BE, et al., Biophysical Journal 2021 (HEK293 cells, in vitro) - [Visualizing oscillations in brain slices with genetically encoded voltage indicators](https://doi.org/10.3389/fnana.2021.741711) — Rhee JK, et al., Frontiers in Neuroanatomy 2021 (Mouse motor cortex brain slices, ex vivo) - [A trafficking motif alters GEVI activity implicating persistent protein interactions at the membrane](https://doi.org/10.1016/j.bpr.2022.100047) — Lee S, et al., Biophysical Reports 2022 (HEK293 cells, in vitro) - [Imaging electrical activity of retinal ganglion cells with fluorescent voltage and calcium indicator proteins in retinal degenerative rd1 blind mice](https://doi.org/10.1021/acschemneuro.5c00740) — Jung Y, et al., ACS Chemical Neuroscience 2025 (Mouse rd1 retinal ganglion cells, ex vivo) ## Bongwoori-R3 Bongwoori variant with an arginine-enriched linker that enlarges the fluorescence response and shifts voltage sensitivity near resting potential for robust action-potential imaging. - Category: VSD-single FP - Published: 2017-08-15 — [Scientific Reports 2017](https://doi.org/10.1038/s41598-017-08731-2) - Derived from: [Bongwoori](https://gevibench.org/gevi/bongwoori) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 488 nm, emission peak 511 nm (Bongwoori-R3) - Plasmid: [Addgene #137838](https://www.addgene.org/137838/) (No plain Bongwoori-R3 plasmid is deposited on Addgene. #137838 is PA-Bongwoori-R3, the photoactivatable derivative from the 2019 follow-up paper (Lee et al. 2019) — a different construct (Bongwoori-R3 fused to a photoactivation module), not the plain 2017 Bongwoori-R3 characterized on this page.) - Tags: pHluorin, Ci-VSP, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.36× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 11 / 10 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -20% (median of 2 measurements: −20%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.1% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 5.9% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 3.0 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 4 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 11 ms, τ_off 10 ms at 34°C — [Lee 2017, Table 2](https://doi.org/10.1038/s41598-017-08731-2) #### ΔF/F per 100 mV - -20%, 1P — [Lee 2017, Fig. 4B](https://doi.org/10.1038/s41598-017-08731-2) - -21%, 2P — [Lee 2017, Fig. 4E](https://doi.org/10.1038/s41598-017-08731-2) #### ΔF/F per action potential - 5.9%, 1P — [Lee 2017, Table 3](https://doi.org/10.1038/s41598-017-08731-2) #### Brightness comparisons - 1.89× the brightness of Bongwoori — [Lee 2017, Table 3](https://doi.org/10.1038/s41598-017-08731-2) #### Photobleaching - t75% = 295 s at 1 mW/mm², 1P — [Lee 2017, Fig. S1](https://doi.org/10.1038/s41598-017-08731-2) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 1%; -70 mV: 0%; -20 mV: -9%; 30 mV: -20%; 80 mV: -26%; 130 mV: -27% — [Lee 2017, Fig. 4B](https://doi.org/10.1038/s41598-017-08731-2) ### Research papers using Bongwoori-R3 (4) - [Improving a genetically encoded voltage indicator by modifying the cytoplasmic charge composition](https://doi.org/10.1038/s41598-017-08731-2) — Lee S, et al., Scientific Reports 2017 (HEK293 cells; cultured mouse hippocampal neurons, in vitro) - [Engineering photoactivatability in genetically encoded voltage and pH indicators](https://doi.org/10.3389/fncel.2019.00482) — Lee S, et al., Frontiers in Cellular Neuroscience 2019 (HEK293 cells, in vitro) - [Visualizing oscillations in brain slices with genetically encoded voltage indicators](https://doi.org/10.3389/fnana.2021.741711) — Rhee JK, et al., Frontiers in Neuroanatomy 2021 (Mouse motor cortex brain slices, ex vivo) - [Imaging electrical activity of retinal ganglion cells with fluorescent voltage and calcium indicator proteins in retinal degenerative rd1 blind mice](https://doi.org/10.1021/acschemneuro.5c00740) — Jung Y, et al., ACS Chemical Neuroscience 2025 (Mouse rd1 retinal ganglion cells, ex vivo) ## CAESR Pioneering opsin-FRET voltage indicator fusing Citrine to the QuasAr2 archaerhodopsin quencher; the prototype of the QuasAr-based eFRET sensor lineage. - Category: eFRET GEVI - Published: 2014-08-13 — [Nature Communications 2014](https://doi.org/10.1038/ncomms5625) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 516 nm, emission peak 529 nm (CAESR) - Tags: Yellow, Citrine, Archaerhodopsin, QuasAr2 ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.43× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 9.9 / 15 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -13.1% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.14% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 9.7% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 9.9 ms, τ_off 14.8 ms at 23°C — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### ΔF/F per 100 mV - -13.1%, 1P — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### ΔF/F per action potential - 9.7%, 1P — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### Brightness comparisons - 1.428× the brightness of EGFP — [Zou 2014, Table S1](https://doi.org/10.1038/ncomms5625) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 4%; -70 mV: 0%; -50 mV: -3%; 0 mV: -8%; 50 mV: -12%; 100 mV: -15% — [Zou 2014, Fig. 4b](https://doi.org/10.1038/ncomms5625) ### Research papers using CAESR (2) - [Bright and fast multicoloured voltage reporters via electrochromic FRET](https://doi.org/10.1038/ncomms5625) — Zou P, Zhao Y, Douglass AD, Hochbaum DR, Brinks D, Werley CA, Harrison DJ, Campbell RE, Cohen AE, Nature Communications 2014 (HEK293 cells, in vitro; cultured rat hippocampal neurons, in vitro) - [Two-photon lifetime imaging of voltage indicating proteins as a probe of absolute membrane voltage](https://doi.org/10.1016/j.bpj.2015.07.038) — Brinks D, Klein AJ, Cohen AE, Biophysical Journal 2015 (HEK293T cells, in vitro) ## Cepheid1b Red eFRET voltage indicator built by inserting the bright RFP donor mScarlet-I1.4 into the first extracellular loop of Ace(D81C) rhodopsin; the brighter (but less photostable) member of the Cepheid1 pair. - Category: eFRET GEVI - Published: 2023-11-24 — [Science Advances 2023](https://doi.org/10.1126/sciadv.adi4208) - Derived from: [VARNAM](https://gevibench.org/gevi/varnam) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 570 nm, emission peak 600 nm (Cepheid1b) - Tags: Ace opsin, mScarlet-I1.4, Red, FRET, Somatic targeting ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.40× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.7 / 5.0 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -31% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.4% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 12.1% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 7 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 17 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.71 ms, τ_off 4.99 ms at 25°C — [Han 2023, Fig. S7B](https://doi.org/10.1126/sciadv.adi4208) - τ_on 2.74 ms, τ_off — ms at 25°C — [Yang 2024, Main text](https://doi.org/10.1101/2024.02.02.578569) #### ΔF/F per 100 mV - -31%, 1P — [Han 2023, Fig. S7A](https://doi.org/10.1126/sciadv.adi4208) #### ΔF/F per action potential - 12.1%, 1P — [Han 2023, Fig. 1C](https://doi.org/10.1126/sciadv.adi4208) #### AP width (FWHM) - 7 ms at 484 Hz sampling, cultured rat hippocampal neurons, in vitro, 1P — [Han 2023, Fig. 1D](https://doi.org/10.1126/sciadv.adi4208) #### Brightness comparisons - 1.65× the brightness of VARNAM — [Han 2023, Fig. S5](https://doi.org/10.1126/sciadv.adi4208) #### Photobleaching - t75% = 108 s at 15.9 mW/mm², 1P — [Han 2023, Fig. S6A](https://doi.org/10.1126/sciadv.adi4208) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 10%; -80 mV: 3%; -70 mV: 0%; -60 mV: -5%; -40 mV: -12%; -20 mV: -19%; 0 mV: -25%; 20 mV: -30%; 40 mV: -33% — [Han 2023, Fig. 1B](https://doi.org/10.1126/sciadv.adi4208) ### Research papers using Cepheid1b (2) - [Bright and sensitive red voltage indicators for imaging action potentials in brain slices and pancreatic islets](https://doi.org/10.1126/sciadv.adi4208) — Han Y, Yang J, Li Y, Chen Y, Ren H, Ding R, Qian W, Ren K, Xie B, Deng M, Xiao Y, Chu J, Zou P, Science Advances 2023 (HEK293T cells, in vitro; rat hippocampal neurons, in vitro; mouse cortex, hippocampus, cerebellum, thalamus, habenula, acute brain slices; mouse pancreatic islets, ex vivo) - [Solaris: a panel of bright and sensitive hybrid voltage indicators for imaging membrane potential in cultured neurons](https://doi.org/10.1101/2024.02.02.578569) — Yang J, Zhu S, Yang L, Peng L, Han Y, Hayward RF, Park P, Hu D, Cohen AE, Zou P, bioRxiv 2024 (HEK293T cells, in vitro (Cepheid1b measured as a comparator: voltage-clamp response half-time τ1/2 = 1.9 ± 0.1 ms at 1058 Hz)) ## Cepheid1s Red eFRET voltage indicator built by inserting the photostable RFP donor mRuby4 into the first extracellular loop of Ace(D81C) rhodopsin; the more photostable (but dimmer) member of the Cepheid1 pair, enabling long-duration one-photon voltage imaging. - Category: eFRET GEVI - Published: 2023-11-24 — [Science Advances 2023](https://doi.org/10.1126/sciadv.adi4208) - Derived from: [VARNAM](https://gevibench.org/gevi/varnam) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 558 nm, emission peak 592 nm (Cepheid1s) - Tags: Ace opsin, mRuby4, Red, FRET, Somatic targeting ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.36× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.0 / 3.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -30% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.4% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 13.3% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 7.9 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.02 ms, τ_off 3.49 ms at 25°C — [Han 2023, Fig. S7B](https://doi.org/10.1126/sciadv.adi4208) - τ_on 2.16 ms, τ_off — ms at 25°C — [Yang 2024, Main text](https://doi.org/10.1101/2024.02.02.578569) #### ΔF/F per 100 mV - -30%, 1P — [Han 2023, Fig. S7A](https://doi.org/10.1126/sciadv.adi4208) #### ΔF/F per action potential - 13.3%, 1P — [Han 2023, Fig. 1C](https://doi.org/10.1126/sciadv.adi4208) #### AP width (FWHM) - 7.9 ms at 484 Hz sampling, cultured rat hippocampal neurons, in vitro, 1P — [Han 2023, Fig. 1D](https://doi.org/10.1126/sciadv.adi4208) #### Brightness comparisons - 0.43× the brightness of VARNAM — [Han 2023, Fig. S5](https://doi.org/10.1126/sciadv.adi4208) #### Photobleaching - curve only (did not reach 75% within the measured window) at 15.9 mW/mm², 1P — [Han 2023, Fig. S6A](https://doi.org/10.1126/sciadv.adi4208) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 12%; -80 mV: 3%; -70 mV: 0%; -60 mV: -5%; -40 mV: -12%; -20 mV: -19%; 0 mV: -25%; 20 mV: -30%; 40 mV: -34% — [Han 2023, Fig. 1B](https://doi.org/10.1126/sciadv.adi4208) ### Research papers using Cepheid1s (2) - [Bright and sensitive red voltage indicators for imaging action potentials in brain slices and pancreatic islets](https://doi.org/10.1126/sciadv.adi4208) — Han Y, Yang J, Li Y, Chen Y, Ren H, Ding R, Qian W, Ren K, Xie B, Deng M, Xiao Y, Chu J, Zou P, Science Advances 2023 (HEK293T cells, in vitro; rat hippocampal neurons, in vitro (Cepheid1s/Cepheid1s-ST characterized for sensitivity, kinetics, brightness, photostability, and used for all-optical electrophysiology with CheRiff and long-term recording)) - [Solaris: a panel of bright and sensitive hybrid voltage indicators for imaging membrane potential in cultured neurons](https://doi.org/10.1101/2024.02.02.578569) — Yang J, Zhu S, Yang L, Peng L, Han Y, Hayward RF, Park P, Hu D, Cohen AE, Zou P, bioRxiv 2024 (HEK293T cells, in vitro (Cepheid1s measured as a comparator: voltage-clamp response half-time τ1/2 = 1.5 ± 0.2 ms at 1058 Hz)) ## ElectraOFF Photostable negative-going eFRET GEVI combining Ace2 opsin with mBaoJin(3M), a StayGold-derived bright and photostable green FP. - Category: eFRET GEVI - Published: 2025-06-03 — [bioRxiv 2025](https://doi.org/10.1101/2025.05.30.657123) - Derived from: [Ace2N-mNeon2](https://gevibench.org/gevi/ace2n-mneon2) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 500 nm, emission peak 508 nm (ElectraOFF) - Tags: Ace opsin, mBaoJin, Green ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 4.86× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.8 / 1.1 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -13% (median of 2 measurements: −13%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.1% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 14.5% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 6.4 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 1.1 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.75 ms, τ_off 1.14 ms at 23-25°C — [Zhang 2025, Fig. S3d](https://doi.org/10.1101/2025.05.30.657123) #### ΔF/F per 100 mV - -13%, 1P — [Zhang 2025, Fig. S3b](https://doi.org/10.1101/2025.05.30.657123) - -18%, 2P — [Zhang 2025, Fig. 3c](https://doi.org/10.1101/2025.05.30.657123) #### ΔF/F per action potential - 14.5%, 1P — [Zhang 2025, Fig. 1k](https://doi.org/10.1101/2025.05.30.657123) #### AP width (FWHM) - 6.4 ms at 1000 Hz sampling, Mouse, primary hippocampal neurons, in vitro, 1P, 22°C — [Zhang 2025, Fig. 1j](https://doi.org/10.1101/2025.05.30.657123) #### Brightness comparisons - 1.6× the brightness of Ace2N-mNeon2 — [Zhang 2025, Fig. 1e](https://doi.org/10.1101/2025.05.30.657123) #### Photobleaching - t75% = 1370 s at 5 mW/mm², 1P — [Zhang 2025, Fig. S4h](https://doi.org/10.1101/2025.05.30.657123) - curve only (did not reach 75% within the measured window) at 10 mW/mm², 1P — [Zhang 2025, Fig. 1h](https://doi.org/10.1101/2025.05.30.657123) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 2%; -80 mV: 1%; -70 mV: 0%; -60 mV: -1%; -40 mV: -3%; -20 mV: -6%; 0 mV: -9%; 20 mV: -12%; 40 mV: -15%; 60 mV: -19% — [Zhang 2025, Fig. S3b](https://doi.org/10.1101/2025.05.30.657123) ### Research papers using ElectraOFF (2) - [Bright and Photostable Voltage Sensors Derived from mBaoJin](https://doi.org/10.1101/2025.05.30.657123) — Zhang H, Zhou S, Kuzmicheva TP, Subach OM, Grimm C, Eom M, Baror-Sebban S, Adam Y, Yoon YG, Emilliani V, Subach FV, Piatkevich KD, bioRxiv 2025 (HEK293T cells; HeLa cells; Mouse, primary hippocampal neurons, in vitro; Mouse, primary visual cortex (VIP+ interneurons), in vivo; Mouse, hippocampus CA1, in vivo; CHO cells (two-photon)) - [Prolonged Single Neuron Voltage Imaging in Behaving Mammals](https://doi.org/10.1101/2025.05.29.656886) — Wang Y, Ravasio C, Yuxin Z, Xue H, bioRxiv 2025 (Mouse, hippocampus CA1 pyramidal neurons, striatal cholinergic interneurons, and visual cortex PV interneurons, in vivo) ## ElectraON Photostable positive-going eFRET GEVI combining pAce with mBaoJin(3M), a StayGold-derived bright and photostable green FP. - Category: eFRET GEVI - Published: 2025-06-03 — [bioRxiv 2025](https://doi.org/10.1101/2025.05.30.657123) - Derived from: [pAce](https://gevibench.org/gevi/pace) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 500 nm, emission peak 508 nm (ElectraON) - Tags: Ace opsin, mBaoJin, Green, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 2.51× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.1 / 0.58 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +10% (median of 2 measurements: +10%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.1% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 22.8% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4.8 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.11 ms, τ_off 0.58 ms at 23-25°C — [Zhang 2025, Fig. S3d](https://doi.org/10.1101/2025.05.30.657123) #### ΔF/F per 100 mV - +10%, 1P — [Zhang 2025, Fig. S3b](https://doi.org/10.1101/2025.05.30.657123) - +10%, 2P — [Zhang 2025, Fig. 3b](https://doi.org/10.1101/2025.05.30.657123) #### ΔF/F per action potential - 22.8%, 1P — [Zhang 2025, Fig. 1k](https://doi.org/10.1101/2025.05.30.657123) #### AP width (FWHM) - 4.8 ms at 1000 Hz sampling, Mouse, primary hippocampal neurons, in vitro (culture), 1P, 22°C — [Zhang 2025, Fig. 1j](https://doi.org/10.1101/2025.05.30.657123) #### Brightness comparisons - 1.3× the brightness of pAce — [Zhang 2025, Fig. 1e](https://doi.org/10.1101/2025.05.30.657123) #### Photobleaching - curve only (did not reach 75% within the measured window) at 5 mW/mm², 1P — [Zhang 2025, Fig. S4h](https://doi.org/10.1101/2025.05.30.657123) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -3%; -80 mV: -1%; -70 mV: 0%; -60 mV: 1%; -40 mV: 3%; -20 mV: 6%; 0 mV: 7%; 20 mV: 9%; 40 mV: 11%; 60 mV: 12% — [Zhang 2025, Fig. S3b](https://doi.org/10.1101/2025.05.30.657123) ### Research papers using ElectraON (1) - [Bright and Photostable Voltage Sensors Derived from mBaoJin](https://doi.org/10.1101/2025.05.30.657123) — Zhang H, Zhou S, Kuzmicheva TP, Subach OM, Grimm C, Eom M, Baror-Sebban S, Adam Y, Yoon YG, Emilliani V, Subach FV, Piatkevich KD, bioRxiv 2025 (HEK293T cells; HeLa cells; Mouse, primary hippocampal neurons, in vitro; Mouse, hippocampus CA1, in vivo; CHO cells, in vitro, two-photon) ## ElectricPk Early voltage indicator using a cpGFP inserted into a voltage-sensing domain. - Category: VSD-cpGFP GEVI - Published: 2012-09-06 — [PLoS ONE 2012](https://doi.org/10.1371/journal.pone.0043454) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 489 nm, emission peak 511 nm (ElectricPk) - Plasmid: [Addgene #40314](https://www.addgene.org/40314/) - Tags: cpEGFP, Fast ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.32× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.2 / 36 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -1.2% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.02% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 0.7% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4.4 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.24 ms, τ_off 35.6 ms at 35-37°C — [Barnett 2012, Fig. 5A](https://doi.org/10.1371/journal.pone.0043454) #### ΔF/F per 100 mV - -1.2% (peak), 1P — [Barnett 2012, Fig. 4A](https://doi.org/10.1371/journal.pone.0043454) #### ΔF/F per action potential - 0.7%, 1P — [Barnett 2012, Fig. 7C](https://doi.org/10.1371/journal.pone.0043454) #### AP width (FWHM) - 4.4 ms at 2000 Hz sampling, Mouse, hippocampal neurons, in vitro, 1P, 35-37°C — [Barnett 2012, Fig. 7B](https://doi.org/10.1371/journal.pone.0043454) #### Brightness comparisons - 0.32× the brightness of EGFP — [doi:estimated from cpEGFP (GCaMP3) EC×QY vs EGFP](estimated from cpEGFP (GCaMP3) EC×QY vs EGFP) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -150 mV: 1.4%; -120 mV: 1%; -100 mV: 0.6%; -70 mV: 0%; -50 mV: -0.4%; 0 mV: -1%; 30 mV: -1.4% — [Barnett 2012, Fig. 6B](https://doi.org/10.1371/journal.pone.0043454) ### Research papers using ElectricPk (1) - [A Fluorescent, Genetically-Encoded Voltage Probe Capable of Resolving Action Potentials](https://doi.org/10.1371/journal.pone.0043454) — Barnett L, Platisa J, Popovic M, Pieribone VA, Hughes T, PLoS ONE 2012 (HEK293 cells, mouse hippocampal neurons, in vitro) ## FlicR1 Red fluorescent GEVI using the same voltage-sensing domain as ArcLight. - Category: VSD-single FP - Published: 2016-02-24 — [Journal of Neuroscience 2016](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) - Derived from: [ElectricPk](https://gevibench.org/gevi/electricpk) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 570 nm, emission peak 597 nm (FlicR1) - Plasmid: [Addgene #74142](https://www.addgene.org/74142/) - Tags: cpmApple, Red, Fast, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.34× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.4 / 3.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +6.6% (median of 3 measurements: +5.5%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.067% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 2.6% (median of 2 measurements: 2%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 6.8 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 48 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 5 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 6.8 ms, τ_off 7.4 ms at 22°C — [Abdelfattah 2016, Table 1](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) - τ_on 3.4 ms, τ_off 3.7 ms at 34°C — [Abdelfattah 2016, Table 1](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) - τ_on 17.4 ms, τ_off 14.2 ms at 25°C — [Kannan 2018, Table S1](https://doi.org/10.1038/s41592-018-0188-7) #### ΔF/F per 100 mV - +6.6%, 1P — [Abdelfattah 2016, Fig. 3D](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) - +2.54%, 1P — [Milosevic 2020, Fig. 2D](https://doi.org/10.1523/ENEURO.0060-20.2020) - +5.5%, 1P — [Kannan 2018, Fig. S2e](https://doi.org/10.1038/s41592-018-0188-7) #### ΔF/F per action potential - 2.6%, 1P — [Abdelfattah 2016, Fig. 5D](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) - 1.4%, 1P — [Beck 2019, Fig. 3d](https://doi.org/10.1038/s41598-019-52370-8) #### AP width (FWHM) - 6.8 ms at 1000 Hz sampling, Cultured rat hippocampal neurons, in vitro, 1P — [Abdelfattah 2016, Fig. 5E](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) #### Brightness comparisons - 1458× the brightness of Arch — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 0.18× the brightness of Ace2N-mNeon — [Kannan 2018, Fig. 1j](https://doi.org/10.1038/s41592-018-0188-7) #### Photobleaching - t75% = 48 s at 100 mW/mm², 1P — [Abdelfattah 2016, Fig. 3I](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) - t50% = 8.6 s at ~1 mW (1120 nm, 2P point scan), 2P — [Abdelfattah 2016, Fig. 4C](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -2%; -80 mV: -1%; -70 mV: 0%; -50 mV: 1%; -20 mV: 3%; 0 mV: 5%; 30 mV: 7%; 50 mV: 8% — [Abdelfattah 2016, Fig. 3D](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) ### Research papers using FlicR1 (5) - [A bright and fast red fluorescent protein voltage indicator that reports neuronal activity in organotypic brain slices](https://doi.org/10.1523/JNEUROSCI.3484-15.2016) — Abdelfattah AS, et al., Journal of Neuroscience 2016 (HEK293 cells; rat hippocampal neurons, in vitro; rat organotypic brain slices) - [Fast, in vivo voltage imaging using a red fluorescent indicator](https://doi.org/10.1038/s41592-018-0188-7) — Kannan M, et al., Nature Methods 2018 (Mouse hippocampus and cortex, in vivo; Drosophila, in vivo) - [A high-speed, bright, red fluorescent voltage sensor to detect neural activity](https://doi.org/10.1038/s41598-019-52370-8) — Beck C, et al., Scientific Reports 2019 (HEK293T cells; cultured rat hippocampal neurons, in vitro) - [In vitro testing of voltage indicators: Archon1, ArcLightD, ASAP1, ASAP2s, ASAP3b, Bongwoori-Pos6, BeRST1, FlicR1, and Chi-VSFP-Butterfly](https://doi.org/10.1523/ENEURO.0060-20.2020) — Milosevic MM, et al., eNeuro 2020 (HEK293 cells, in vitro) - [Screening and cellular characterization of genetically encoded voltage indicators based on near-infrared fluorescent proteins](https://doi.org/10.1021/acschemneuro.0c00046) — Piatkevich KD, et al., ACS Chemical Neuroscience 2020 (HEK293T cells; cultured neurons, in vitro) ## FlicR2 Directed-evolution variant of FlicR1 with roughly doubled voltage sensitivity, retaining the red cpmApple fluorescent reporter. - Category: VSD-single FP - Published: 2018-11-12 — [Nature Methods 2018](https://doi.org/10.1038/s41592-018-0188-7) - Derived from: [FlicR1](https://gevibench.org/gevi/flicr1) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 567 nm, emission peak 592 nm (FlicR2) - Tags: cpmApple, Red, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.50× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 16 / 16 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +12.9% (median of 2 measurements: +12.9%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.14% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 16.2 ms, τ_off 15.8 ms at 22-25°C — [Kannan 2018, Table S1](https://doi.org/10.1038/s41592-018-0188-7) #### ΔF/F per 100 mV - +12.9%, 1P — [Kannan 2018, Fig. S2e](https://doi.org/10.1038/s41592-018-0188-7) - +24%, 2P — [Yang 2026, Fig. 2D](https://doi.org/10.64898/2026.06.01.726307) #### Brightness comparisons - 0.18× the brightness of Ace2N-mNeon — [Kannan 2018, Fig. 1j](https://doi.org/10.1038/s41592-018-0188-7) - 1.1764705882352942× the brightness of VADER1 — [Yang 2026, Fig. 2C](https://doi.org/10.64898/2026.06.01.726307) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: -5%; -100 mV: -5%; -70 mV: 0%; -50 mV: 2%; -40 mV: 4%; -20 mV: 11%; 0 mV: 20%; 30 mV: 24%; 50 mV: 27%; 70 mV: 27%; 90 mV: 25% — [Yang 2026, Fig. 2D](https://doi.org/10.64898/2026.06.01.726307) ### Research papers using FlicR2 (2) - [Fast, in vivo voltage imaging using a red fluorescent indicator](https://doi.org/10.1038/s41592-018-0188-7) — Kannan M, Vasan G, Huang C, Haziza S, Li JZ, Inan H, Schnitzer MJ, Pieribone VA, Nature Methods 2018 (HEK cells, in vitro) - [A red-emitting, genetically encoded indicator for two-photon voltage recording in vivo](https://doi.org/10.64898/2026.06.01.726307) — Yang S, McDonald AJ, Lu X, Villette V, Hakam N, Galdamez M, et al., bioRxiv 2026 (CHO cells, in vitro; HEK293A cells, in vitro; HEK-Kir2.1 cells, in vitro) ## FORCE1s Positive-going variant evolved from JEDI-2P with substantially larger spike responses, high intrinsic brightness, and repolarization kinetics tuned for 2P imaging. - Category: VSD-cpGFP GEVI - Published: 2026-04-10 — [bioRxiv 2026](https://doi.org/10.64898/2026.04.07.717088) - Derived from: [JEDI-2P](https://gevibench.org/gevi/jedi2p) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 489 nm, emission peak 516 nm (FORCE1s) - Two-photon compatible: yes - Tags: cpGFP, Green, Positive-going, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.22× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.7 / 6.0 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +267% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.2% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 92.7% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 3.8 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 3.72 ms, τ_off 5.95 ms at 33°C — [McDonald 2026, Table S1.4](https://doi.org/10.64898/2026.04.07.717088) #### ΔF/F per 100 mV - +267%, 2P — [McDonald 2026, Fig. 1E](https://doi.org/10.64898/2026.04.07.717088) #### ΔF/F per mV (subthreshold) - 1.2%/mV — [McDonald 2026, Fig. 2F](https://doi.org/10.64898/2026.04.07.717088) #### ΔF/F per action potential - 92.7%, 2P — [McDonald 2026, Fig. 3B](https://doi.org/10.64898/2026.04.07.717088) #### AP width (FWHM) - 2.6 ms at 7100 Hz sampling, Mouse, visual cortex L2/3, awake head-fixed, in vivo (ULoVE 2P), soma-targeted FORCE1s-Kv, 2P, 37°C — [McDonald 2026, Fig. 3E](https://doi.org/10.64898/2026.04.07.717088) - 4.9 ms at 721 Hz sampling, HEK293A cells, whole-cell voltage clamp, in vitro (2-ms FWHM command AP waveform), 2P, 33°C — [McDonald 2026, Fig. 1K](https://doi.org/10.64898/2026.04.07.717088) #### Brightness comparisons - 0.39× the brightness of JEDI-2P — [McDonald 2026, Fig. 1C](https://doi.org/10.64898/2026.04.07.717088) - 2× the brightness of ASAP4e — [McDonald 2026, Fig. 1C](https://doi.org/10.64898/2026.04.07.717088) #### Photobleaching - t75% = 65 s at 100 mW at sample plane (2P, 940 nm), 2P — [McDonald 2026, Fig. S1.2B](https://doi.org/10.64898/2026.04.07.717088) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: -46%; -100 mV: -34%; -80 mV: -13%; -70 mV: 0%; -60 mV: 21%; -40 mV: 88%; -20 mV: 169%; 0 mV: 227%; 20 mV: 252%; 30 mV: 267%; 50 mV: 282% — [McDonald 2026, Fig. 1E](https://doi.org/10.64898/2026.04.07.717088) ### Research papers using FORCE1s (1) - [A versatile, positive-going voltage indicator that enables accessible two-photon recordings in vivo](https://doi.org/10.64898/2026.04.07.717088) — McDonald AJ, Land MA, Yang S, et al., bioRxiv 2026 (Mouse, visual cortex L2/3, in vivo; Mouse, visual cortex, freely moving, in vivo; HEK293 cells, in vitro; Rat, hippocampal neurons, in vitro) ## HArclight1 Chemigenetic adaptation of the ArcLight architecture that replaces the pH-sensitive GFP with a HaloTag labeled with a far-red Si-rhodamine dye, giving negative-going fluorescence responses to depolarization. - Category: Chemigenetic GEVI - Published: 2021-04-01 — [Nature Chemical Biology 2021](https://doi.org/10.1038/s41589-021-00775-w) - Derived from: [ArcLight](https://gevibench.org/gevi/arclight) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 642 nm, emission peak 655 nm (HArclight1 (JF635)) - Plasmid: [Addgene #138326](https://www.addgene.org/138326/) - Tags: HaloTag, Far-red, Negative-going, JF635, ArcLight topology ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.81× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 5.1 / 5.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -3.5% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.05% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 5.1 ms, τ_off 5.7 ms at 25°C — [Deo 2021, Table S6](https://doi.org/10.1038/s41589-021-00775-w) #### ΔF/F per 100 mV - -3.5%, 1P, dye JF635 — [Deo 2021, Fig. 4h](https://doi.org/10.1038/s41589-021-00775-w) #### Brightness comparisons - 1.808× the brightness of EGFP — [Deo 2021, Table S4](https://doi.org/10.1038/s41589-021-00775-w) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -110 mV: 1%; -90 mV: 0.8%; -70 mV: 0%; -50 mV: -1.2%; -30 mV: -2%; -10 mV: -2.5%; 10 mV: -3%; 30 mV: -3.5%; 50 mV: -4% — [Deo 2021, Fig. 4h](https://doi.org/10.1038/s41589-021-00775-w) ### Research papers using HArclight1 (1) - [The HaloTag as a general scaffold for far-red tunable chemigenetic indicators](https://doi.org/10.1038/s41589-021-00775-w) — Deo C, Abdelfattah AS, Bhargava HK, Berro AJ, Falco N, Farrants H, Moeyaert B, Chupanova M, Lavis LD, Schreiter ER, Nature Chemical Biology 2021 (Rat hippocampal neurons, in vitro) ## HASAP1 Chemigenetic adaptation of the ASAP architecture that replaces cpGFP with cpHaloTag labeled with a far-red Si-rhodamine dye, giving positive-going fluorescence responses to depolarization. - Category: Chemigenetic GEVI - Published: 2021-04-01 — [Nature Chemical Biology 2021](https://doi.org/10.1038/s41589-021-00775-w) - Derived from: [ASAP1](https://gevibench.org/gevi/asap1) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 642 nm, emission peak 655 nm (HASAP1 (JF635)) - Plasmid: [Addgene #138325](https://www.addgene.org/138325/) - Tags: cpHaloTag, Far-red, Positive-going, JF635 ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.81× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.2 / 2.4 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +9.3% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.075% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 3.7% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 15 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.22 ms, τ_off 2.4 ms at 25°C — [Deo 2021, Table S6](https://doi.org/10.1038/s41589-021-00775-w) #### ΔF/F per 100 mV - +9.3%, 1P, dye JF635 — [Deo 2021, Fig. 4e](https://doi.org/10.1038/s41589-021-00775-w) #### ΔF/F per action potential - 3.7%, 1P, dye JF635 — [Deo 2021, Fig. 4i](https://doi.org/10.1038/s41589-021-00775-w) #### AP width (FWHM) - 15.3 ms at 400 Hz sampling, Rat, dissociated hippocampal neurons, in vitro (culture), 1P — [Deo 2021, Fig. 4i](https://doi.org/10.1038/s41589-021-00775-w) #### Brightness comparisons - 1.808× the brightness of EGFP — [Deo 2021, Table S4](https://doi.org/10.1038/s41589-021-00775-w) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -110 mV: -3%; -90 mV: -2%; -70 mV: 0%; -50 mV: 1%; -30 mV: 2%; -10 mV: 4%; 10 mV: 6%; 30 mV: 9%; 50 mV: 13% — [Deo 2021, Fig. 4e](https://doi.org/10.1038/s41589-021-00775-w) ### Research papers using HASAP1 (1) - [The HaloTag as a general scaffold for far-red tunable chemigenetic indicators](https://doi.org/10.1038/s41589-021-00775-w) — Deo C, Abdelfattah AS, Bhargava HK, Berro AJ, Falco N, Farrants H, Moeyaert B, Chupanova M, Lavis LD, Schreiter ER, Nature Chemical Biology 2021 (Rat hippocampal neurons, in vitro) ## HVI Chemigenetic GEVI that conjugates dyes to an Ace2 rhodopsin. - Category: Chemigenetic GEVI - Published: 2021-04-15 — [Nature Chemistry 2021](https://doi.org/10.1038/s41557-021-00641-1) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 553 nm, emission peak 569 nm (HVI (Cy3)) - Tags: Ace opsin, Cy3 ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 2.10× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.7 / 2.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -39.1% (median of 3 measurements: −39.1%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.28% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 25.3% (median of 3 measurements: 25.3%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 12 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 1.2 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 3 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.7 ms, τ_off 2.5 ms at 25°C — [Liu 2021, Table S3](https://doi.org/10.1038/s41557-021-00641-1) - τ_on 2.27 ms, τ_off 4.35 ms at 25°C — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) - τ_on 2.16 ms, τ_off 4.1 ms at 25°C — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) #### ΔF/F per 100 mV - -39.1%, 1P, dye Cy3 — [Liu 2021, Table S3](https://doi.org/10.1038/s41557-021-00641-1) - -61.3%, 1P, dye Cy3b — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) - -19.6%, 1P, dye Cy5 — [Liu 2021, Table S3](https://doi.org/10.1038/s41557-021-00641-1) #### ΔF/F per mV (subthreshold) - 0.28%/mV (HVI-Cy3: ΔF/F0 responses of −4.7 ± 0.1% and −2.2 ± 0.1% to depolarizing subthreshold steps of +16.9 and +7.8 mV, and +2.2 ± 0.1% and +4.8 ± 0.1% to hyperpolarizing steps of −7.4 and −17.2 mV, at a resting potential of ~−68 mV in cultured rat hippocampal neurons (484 Hz, 532 nm). |ΔF/F0|/|ΔV| ≈ 0.28 %/mV across all four steps.) — [Liu 2021, Table S5](https://doi.org/10.1038/s41557-021-00641-1) #### ΔF/F per action potential - 25.3%, 1P, dye Cy3 — [Liu 2021, Table S3](https://doi.org/10.1038/s41557-021-00641-1) - -39.6%, 1P, dye Cy3b — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) - -12.8%, 1P, dye Cy5 — [Liu 2021, Table S3](https://doi.org/10.1038/s41557-021-00641-1) #### AP width (FWHM) - 12 ms at 200 Hz sampling, Mouse, pancreatic islet α cells, ex vivo, 1P, 37°C — [Liu 2025, Fig. 6F](https://doi.org/10.1126/sciadv.ads1807) #### Brightness comparisons - 0.19× the brightness of Voltron — [Liu 2021, Table S4](https://doi.org/10.1038/s41557-021-00641-1) - 1.8867924528301885× the brightness of HVI+ — [Liu 2025, Fig. S5C](https://doi.org/10.1126/sciadv.ads1807) #### Photobleaching - t75% = 220 s at 49 mW/mm², 1P — [Liu 2021, Ext. Fig. 4g](https://doi.org/10.1038/s41557-021-00641-1) - t75% = 143 s at 50 mW/mm², 1P — [Liu 2025, Fig. S7](https://doi.org/10.1126/sciadv.ads1807) - t75% = 42 s at 12 mW/mm², 1P — [Liu 2021, Ext. Fig. 4g](https://doi.org/10.1038/s41557-021-00641-1) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 17%; -80 mV: 6%; -70 mV: 0%; -60 mV: -6%; -40 mV: -16%; -20 mV: -25%; 0 mV: -33%; 20 mV: -40%; 40 mV: -45%; 60 mV: -50% — [Liu 2021, Fig. 2b](https://doi.org/10.1038/s41557-021-00641-1) ### Research papers using HVI (3) - [A far-red hybrid voltage indicator enabled by bioorthogonal engineering of rhodopsin on live neurons](https://doi.org/10.1038/s41557-021-00641-1) — Liu S, Lin C, Xu Y, et al., Nature Chemistry 2021 (Human, HEK293T cells, in vitro; rat, hippocampal neurons, in vitro) - [Orange/far-red hybrid voltage indicators with reduced phototoxicity enable reliable long-term imaging in neurons and cardiomyocytes](https://doi.org/10.1073/pnas.2306950120) — Liu S, Ling J, Chen P, et al., Proceedings of the National Academy of Sciences 2023 (Rat, hippocampal neurons, in vitro; rat, cardiomyocytes, in vitro) - [Positive-going hybrid indicators for voltage imaging in excitable cells and tissues](https://doi.org/10.1126/sciadv.ads1807) — Liu S, Ling J, Xie B, et al., Science Advances 2025 (Rat, hippocampal neurons, in vitro; mouse, pancreatic islets) ## HVI+ Positive-going variant of chemigenetic voltage indicator HVI. - Category: Chemigenetic GEVI - Published: 2025-08-08 — [Science Advances 2025](https://doi.org/10.1126/sciadv.ads1807) - Derived from: [HVI](https://gevibench.org/gevi/hvi) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 556 nm, emission peak 571 nm (HVI+ (Cy3b)) - Tags: Ace opsin, Cy3b, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.11× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 6.8 / 5.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +55% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.22% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 22.3% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 9.5 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 3.2 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 6.77 ms, τ_off 5.48 ms at 25°C — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) #### ΔF/F per 100 mV - +55%, 1P, dye Cy3b — [Liu 2025, Fig. 2E](https://doi.org/10.1126/sciadv.ads1807) #### ΔF/F per mV (subthreshold) - 0.22%/mV — [Liu 2025, Fig. 2G](https://doi.org/10.1126/sciadv.ads1807) #### ΔF/F per action potential - 22.3%, 1P, dye Cy3b — [Liu 2025, Fig. 2C](https://doi.org/10.1126/sciadv.ads1807) #### AP width (FWHM) - 5 ms at 1000 Hz sampling, Rat, cultured hippocampal neurons, in vitro, 1P, 25°C — [Liu 2025, Fig. 3B](https://doi.org/10.1126/sciadv.ads1807) - 14 ms at 200 Hz sampling, Mouse, pancreatic islet β cells, ex vivo, 1P, 37°C — [Liu 2025, Fig. 6F](https://doi.org/10.1126/sciadv.ads1807) #### Brightness comparisons - 0.53× the brightness of HVI — [Liu 2025, Fig. S5C](https://doi.org/10.1126/sciadv.ads1807) #### Photobleaching - t75% = 381 s at 50 mW/mm², 1P — [Liu 2025, Fig. S7](https://doi.org/10.1126/sciadv.ads1807) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -10%; -80 mV: -5%; -70 mV: 0%; -60 mV: 6%; -40 mV: 15%; -20 mV: 25%; 0 mV: 37%; 20 mV: 47%; 40 mV: 57%; 60 mV: 67%; 80 mV: 78%; 100 mV: 88% — [Liu 2025, Fig. 2E](https://doi.org/10.1126/sciadv.ads1807) ### Research papers using HVI+ (1) - [Positive-going hybrid indicators for voltage imaging in excitable cells and tissues](https://doi.org/10.1126/sciadv.ads1807) — Liu S, et al., Science Advances 2025 (Rat, hippocampal neurons, in vitro; rat, cardiomyocytes, in vitro; mouse, pancreatic islets, ex vivo) ## Jarvis Variant of pAce with the ultra-bright AausFP1 fluorophore, yielding a high-contrast positive-going FRET-opsin indicator compatible with 2P voltage imaging. - Category: eFRET GEVI - Published: 2026-02-12 — [Neuron 2026](https://doi.org/10.1016/j.neuron.2025.12.014) - Derived from: [pAce](https://gevibench.org/gevi/pace) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 504 nm, emission peak 510 nm (Jarvis) - Two-photon compatible: yes - Tags: Ace opsin, AausFP1, Green, Positive, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.39× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.7 / 1.9 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +29% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.2% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 25% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 1.7 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 2.1 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.74 ms, τ_off 1.88 ms at 25°C — [Grimm 2026, Fig. 1D](https://doi.org/10.1016/j.neuron.2025.12.014) #### ΔF/F per 100 mV - +29%, 1P — [Grimm 2026, Fig. 1C(i)](https://doi.org/10.1016/j.neuron.2025.12.014) #### ΔF/F per action potential - 25%, 1P — [Grimm 2026, Fig. 1G(ii)](https://doi.org/10.1016/j.neuron.2025.12.014) #### AP width (FWHM) - 1.73 ms at 1000 Hz sampling, Mouse, organotypic hippocampal slice, in vitro, 1P, 25°C — [Grimm 2026, Fig. 1G(i)](https://doi.org/10.1016/j.neuron.2025.12.014) #### Brightness comparisons - 0.42× the brightness of pAce — [Grimm 2026, Fig. 1C](https://doi.org/10.1016/j.neuron.2025.12.014) - 4.08× the brightness of JEDI-2P — [Grimm 2026, Fig. 1C](https://doi.org/10.1016/j.neuron.2025.12.014) #### Photobleaching - t75% = 317 s (extrapolated), 1P — [Grimm 2026, Fig. 1F](https://doi.org/10.1016/j.neuron.2025.12.014) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -90 mV: -4%; -80 mV: -2%; -70 mV: 0%; -60 mV: 2%; -50 mV: 4%; -40 mV: 7%; -30 mV: 11%; -20 mV: 14%; -10 mV: 17%; 0 mV: 21%; 10 mV: 24%; 20 mV: 26%; 30 mV: 29% — [Grimm 2026, Fig. 1E](https://doi.org/10.1016/j.neuron.2025.12.014) ### Research papers using Jarvis (1) - [Two-photon voltage imaging with rhodopsin-based sensors](https://doi.org/10.1016/j.neuron.2025.12.014) — Grimm C, Sims RR, Tanese D, Lafirdeen ASM, Bendifallah I, Chan CY, Faini G, Putti E, Del Bene F, Papagiakoumou E, Emiliani V, Neuron 2026 (ND7/23 cells, in vitro; CHO cells, in vitro; Mouse, organotypic hippocampal slices, in vitro; Zebrafish larvae, olfactory epithelium, in vivo) ## JEDI-1P One-photon optimized GEVI evolved from ASAP2s with improved brightness, kinetics, and sensitivity. - Category: VSD-cpGFP GEVI - Published: 2023-10-12 — [Nature Communications 2023](https://doi.org/10.1038/s41467-023-41975-3) - Derived from: [ASAP2s](https://gevibench.org/gevi/asap2s) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 487 nm, emission peak 509 nm (JEDI-1P) - Plasmid: [Addgene #202613](https://www.addgene.org/202613/) - Tags: cpGFP ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.89× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 5.1 / 6.2 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -56% (median of 3 measurements: −66%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.9% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 31.2% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4.9 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 54 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 7 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.58 ms, τ_off 1.2 ms at 32-35°C — [Lu 2023, Table 1](https://doi.org/10.1038/s41467-023-41975-3) - τ_on 5.41 ms, τ_off 2.91 ms at 21-23°C — [Lu 2023, Table 1](https://doi.org/10.1038/s41467-023-41975-3) - τ_on 10.86 ms, τ_off 14.11 ms at 23°C — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) - τ_on 8.69 ms, τ_off 11.11 ms at 37°C — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per 100 mV - -56%, 1P — [Lu 2023, Fig. 2c](https://doi.org/10.1038/s41467-023-41975-3) - -66.3%, 1P — [Cao 2025, Fig. 1C](https://doi.org/10.1101/2025.05.29.656768) - -66%, 1P — [Rühl 2026, Table S1](https://doi.org/10.64898/2026.02.10.701308) #### ΔF/F per mV (subthreshold) - 0.9%/mV (Subthreshold fluorescence-per-voltage conversion ratio = 0.9% per mV for JEDI-1P (vs 1.3% for ASAP5, 0.9% for ASAP3, 0.7% for JEDI-2P), stated in the main text and quantified in Figure S1C of the ASAP5/Hao paper. The normalized F-V slope is also shown in main Fig. 1D.) — [Hao 2024, Fig. S1C](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per action potential - 31.2%, 1P — [Lu 2023, Fig. 2e](https://doi.org/10.1038/s41467-023-41975-3) #### AP width (FWHM) - 4.9 ms at 1000 Hz sampling, HEK293A cells, optical response to a single AP-like command waveform, whole-cell voltage clamp, 1P, 32-35°C — [Lu 2023, Fig. 2f](https://doi.org/10.1038/s41467-023-41975-3) #### Brightness comparisons - 2.44× the brightness of ASAP3 — [Lu 2023, Fig. 2h](https://doi.org/10.1038/s41467-023-41975-3) - 2.2× the brightness of ASAP2s — [Lu 2023, Fig. 2h](https://doi.org/10.1038/s41467-023-41975-3) - 1.71× the brightness of ASAP3 — [Nair 2025, Fig. 2C](https://doi.org/10.1021/acschemneuro.5c00670) - 0.125× the brightness of Vega — [Cao 2025, Fig. 1B](https://doi.org/10.1101/2025.05.29.656768) - 1.3550135501355014× the brightness of rEstus2s — [Rühl 2026, Table S1](https://doi.org/10.64898/2026.02.10.701308) #### Photobleaching - t75% = 112 s at 30 mW/mm², 1P — [Cao 2025, Fig. 1D](https://doi.org/10.1101/2025.05.29.656768) - t50% = 160 s (extrapolated) at 46 mW/mm², 1P — [Lu 2023, Fig. S4](https://doi.org/10.1038/s41467-023-41975-3) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 12%; -70 mV: 0%; -40 mV: -22%; -20 mV: -37%; 0 mV: -47%; 20 mV: -55%; 30 mV: -56%; 50 mV: -58% — [Lu 2023, Fig. 2b](https://doi.org/10.1038/s41467-023-41975-3) ### Research papers using JEDI-1P (7) - [Widefield imaging of rapid pan-cortical voltage dynamics with an indicator evolved for one-photon microscopy](https://doi.org/10.1038/s41467-023-41975-3) — Lu X, Wang Y, Liu Z, Gou Y, Jaeger D, St-Pierre F, Nature Communications 2023 (Mouse, cortex, in vivo; HEK293T cells, in vitro; dissociated hippocampal neurons) - [Cortex-wide voltage imaging in a sensory cued reaching task reveals fast subnetwork dynamics](https://doi.org/10.1101/2025.04.24.650533) — Wang Y, Kim SH, He EJ, Le Chatelier B, Choi H, Jaeger D, bioRxiv 2025 (Mouse, cortex, in vivo) - [A fast and responsive voltage indicator with enhanced sensitivity for unitary synaptic events](https://doi.org/10.1016/j.neuron.2024.08.019) — Hao YA, Lee S, Roth RH, et al., Neuron 2024 (Mouse, motor cortex, in vivo) - [Absolute Membrane Potential Recording with ASAP-Type Genetically Encoded Voltage Indicators Using Fluorescence Lifetime Imaging](https://doi.org/10.1021/acschemneuro.5c00670) — Nair AG, Rodewald M, Bae H, Rühl P, Popp J, Schmitt M, Meyer-Zedler T, Heinemann SH, ACS Chemical Neuroscience 2025 (HEK293T cells, in vitro) - [An integrated platform for simultaneous wide-field voltage/calcium imaging and fMRI reveals neuronal infraslow dynamics underlying functional connectivity](https://doi.org/10.64898/2026.01.26.701889) — Pan WJ, Daley L, Watters H, Meyer-Baese L, Gopinath K, Jaeger D, Keilholz S, bioRxiv 2026 (Mouse, cortex, in vivo) - [A photostable genetically encoded voltage indicator for imaging neural activities in tissue and live animals](https://doi.org/10.1101/2025.05.29.656768) — Cao C, Zhu R, Zhou S, Zhao Z, Lin C, Liu S, Peng L, Subach FV, Piatkevich KD, Zou P, bioRxiv 2025 (HEK293T cells, in vitro) - [Sub-Millivolt Voltage Imaging Reveals Gap Junction-Mediated Bioelectric Contact Inhibition](https://doi.org/10.64898/2026.02.10.701308) — Rühl P, Hussein R, Reuter S, Frahnert K, Nair AG, Mrowka R, Schönherr R, Heinemann SH, bioRxiv 2026 (HEK293T cells, in vitro (whole-cell voltage clamp; JEDI-1P R-V curve characterized alongside rEstus2s)) ## JEDI-2P Two-photon optimized GEVI evolved from ASAP2s with improved brightness, photostability, and sensitivity under two-photon illumination. - Category: VSD-cpGFP GEVI - Published: 2022-08-18 — [Cell 2022](https://doi.org/10.1016/j.cell.2022.07.013) - Derived from: [ASAP2s](https://gevibench.org/gevi/asap2s) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 501 nm, emission peak 519 nm (JEDI-2P) - Two-photon compatible: yes - Plasmid: [Addgene #179463](https://www.addgene.org/179463/) - Tags: cpGFP, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.51× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.1 / 2.8 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -48% (median of 5 measurements: −45.5%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.7% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 18.2% (median of 6 measurements: 24%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 1.6 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 14 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 14 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.45 ms, τ_off 1.21 ms at 32-35°C — [Liu 2022, Table S2](https://doi.org/10.1016/j.cell.2022.07.013) - τ_on 2.47 ms, τ_off 2.54 ms at 21-23°C — [Liu 2022, Table S2](https://doi.org/10.1016/j.cell.2022.07.013) - τ_on 0.91 ms, τ_off 1.5 ms at 33°C — [McDonald 2026, Table S1.4](https://doi.org/10.64898/2026.04.07.717088) - τ_on 1.6 ms, τ_off 1.2 ms at 33°C — [Land 2026, Table 1](https://doi.org/10.1038/s41592-026-03043-8) - τ_on 4.57 ms, τ_off 3.8 ms at 23°C — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) - τ_on 4.3 ms, τ_off 7.28 ms at 37°C — [Hao 2024, Table S2](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per 100 mV - -48%, 2P — [Liu 2022, Fig. 2C](https://doi.org/10.1016/j.cell.2022.07.013) - -45%, 1P — [Liu 2022, Fig. S4C](https://doi.org/10.1016/j.cell.2022.07.013) - -46%, 1P — [Grimm 2026, Fig. 1C(i)](https://doi.org/10.1016/j.neuron.2025.12.014) - -41.8%, 2P — [Land 2026, Fig. 1h](https://doi.org/10.1038/s41592-026-03043-8) - -41.73%, 2P — [Land 2026, Ext. Fig. 1b](https://doi.org/10.1038/s41592-026-03043-8) #### ΔF/F per mV (subthreshold) - 0.7%/mV — [Hao 2024, Fig. 1D](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per action potential - 18.2%, 2P — [Liu 2022, Fig. 5D](https://doi.org/10.1016/j.cell.2022.07.013) - 26%, 2P — [Liu 2022, Fig. 2E](https://doi.org/10.1016/j.cell.2022.07.013) - 24%, 1P — [Liu 2022, Fig. S4E](https://doi.org/10.1016/j.cell.2022.07.013) - 23.3%, 2P — [Land 2026, Fig. 1j](https://doi.org/10.1038/s41592-026-03043-8) - 28.6%, 2P — [Yang 2026, Fig. 3B](https://doi.org/10.64898/2026.06.01.726307) - 27.6%, 2P — [McDonald 2026, Fig. 3B](https://doi.org/10.64898/2026.04.07.717088) #### AP width (FWHM) - 1.4 ms at 7142.9 Hz sampling, Mouse, visual cortex L2/3, awake head-fixed, in vivo, 2P, 37°C — [Yang 2026, Fig. 3C](https://doi.org/10.64898/2026.06.01.726307) - 5.6 ms at 20000 Hz sampling, HEK293A cells, whole-cell voltage clamp, in vitro (2-ms FWHM command AP waveform), 2P, 23°C — [Land 2026, Fig. 1k](https://doi.org/10.1038/s41592-026-03043-8) - 1.4 ms at 1000 Hz sampling, Mouse visual cortex, awake behaving, in vivo, soma-targeted JEDI-2P-Kv (ULoVE 2P), 2P, 37°C — [Land 2026, Fig. 2d](https://doi.org/10.1038/s41592-026-03043-8) - 1.4 ms at 7100 Hz sampling, Mouse, visual cortex L2/3, awake head-fixed, in vivo (ULoVE 2P), soma-targeted JEDI-2P-Kv, 2P, 37°C — [McDonald 2026, Fig. 3E](https://doi.org/10.64898/2026.04.07.717088) - 3.6 ms at 721 Hz sampling, HEK293A cells, whole-cell voltage clamp, in vitro (2-ms FWHM command AP waveform), 2P, 33°C — [McDonald 2026, Fig. 1K](https://doi.org/10.64898/2026.04.07.717088) - 2.1 ms at 4400 Hz sampling, Mouse, visual cortex L2/3, anesthetized, in vivo (2P, paired juxtacellular), 2P, 37°C — [Liu 2022, Fig. 5D](https://doi.org/10.1016/j.cell.2022.07.013) - 1.84 ms at 3500 Hz sampling, Mouse, V1 cortex layer II/III, awake behaving, in vivo (JEDI-2P-Kv, ULoVE 2P), 2P, 37°C — [Villette 2024, Fig. 3f](https://doi.org/10.1101/2024.11.15.623698) - 0.72 ms at 3500 Hz sampling, Mouse, cerebellar granular layer, fast-spiking Glyt2+ Golgi interneurons, awake behaving, in vivo (JEDI-2P, ULoVE 2P), 2P, 37°C — [Villette 2024, Fig. S9](https://doi.org/10.1101/2024.11.15.623698) #### Brightness comparisons - 1.67× the brightness of ASAP3 — [Liu 2022, Fig. 2I](https://doi.org/10.1016/j.cell.2022.07.013) - 1.5× the brightness of ASAP2s — [Liu 2022, Fig. 2I](https://doi.org/10.1016/j.cell.2022.07.013) - 1.45× the brightness of ASAP5 — [Land 2026, Ext. Fig. 1c](https://doi.org/10.1038/s41592-026-03043-8) - 0.24271844660194175× the brightness of 2Photron — [Villette 2024, Fig. 3f](https://doi.org/10.1101/2024.11.15.623698) - 2.564102564102564× the brightness of FORCE1s — [McDonald 2026, Fig. 1C](https://doi.org/10.64898/2026.04.07.717088) - 0.24509803921568626× the brightness of Jarvis — [Grimm 2026, Fig. 1C](https://doi.org/10.1016/j.neuron.2025.12.014) - 1.1627906976744187× the brightness of JEDI-3hyp — [Land 2026, Fig. 1d](https://doi.org/10.1038/s41592-026-03043-8) - 1.0416666666666667× the brightness of JEDI-3sub — [Land 2026, Fig. 1d](https://doi.org/10.1038/s41592-026-03043-8) #### Photobleaching - t75% = 64 s at 37 mW at sample plane (2P), 2P — [Land 2026, Fig. 1e](https://doi.org/10.1038/s41592-026-03043-8) - t75% = 44 s, 1P — [Grimm 2026, Fig. 1F](https://doi.org/10.1016/j.neuron.2025.12.014) - t75% = 14 s at 100 mW at sample plane (2P, 940 nm), 2P — [McDonald 2026, Fig. S1.2B](https://doi.org/10.64898/2026.04.07.717088) - t75% = 234 s at 22.5 mW at 1045 nm (ULoVE 2P, brain surface), 2P — [Yang 2026, Fig. 3F](https://doi.org/10.64898/2026.06.01.726307) - t50% = 65 s, 1P — [Liu 2022, Fig. S4G](https://doi.org/10.1016/j.cell.2022.07.013) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 10%; -80 mV: 3%; -60 mV: -5%; -40 mV: -20%; -20 mV: -34%; 0 mV: -43%; 20 mV: -47%; 30 mV: -48%; 50 mV: -49% — [Liu 2022, Fig. 2B](https://doi.org/10.1016/j.cell.2022.07.013) ### Research papers using JEDI-2P (14) - [Sustained deep-tissue voltage recording using a fast indicator evolved for two-photon microscopy](https://doi.org/10.1016/j.cell.2022.07.013) — Liu Z, Lu X, Villette V, et al., Cell 2022 (HEK293 cells, in vitro; Mouse, visual cortex L2/3, in vivo; Drosophila, interneurons, ex vivo; Mouse, retina, ex vivo) - [Scanless two-photon voltage imaging](https://doi.org/10.1038/s41467-024-49192-2) — Sims RR, et al., Nature Communications 2024 (Mouse, hippocampal slices, in vitro; Mouse, barrel cortex, in vivo) - [A fast and responsive voltage indicator with enhanced sensitivity for unitary synaptic events](https://doi.org/10.1016/j.neuron.2024.08.019) — Hao YA, et al., Neuron 2024 (Rat, cultured neurons, in vitro; Mouse, cortex, in vivo) - [A novel rhodopsin-based voltage indicator for simultaneous two-photon optical recording with GCaMP in vivo](https://doi.org/10.1101/2024.11.15.623698) — Villette V, et al., bioRxiv 2024 (Mouse, visual cortex, in vivo) - [Two-photon voltage imaging with rhodopsin-based sensors](https://doi.org/10.1016/j.neuron.2025.12.014) — Grimm C, et al., Neuron 2026 (HEK293 cells, in vitro; Mouse, cortex and cerebellum, in vivo) - [All-optical voltage interrogation for probing synaptic plasticity in vivo](https://doi.org/10.1038/s41467-025-63867-4) — Carolan J, et al., Nature Communications 2025 (Mouse, cerebellum, Purkinje cell dendrites, in vivo) - [FACED 2.0 enables large-scale voltage and calcium imaging in vivo](https://doi.org/10.1038/s41592-025-02925-7) — Zhong J, et al., Nature Methods 2025 (Mouse, visual cortex L2/3, in vivo; Zebrafish larvae, in vivo) - [Retroreflective beam multiplexing enables high-throughput two-photon voltage imaging in vivo](https://doi.org/10.64898/2025.12.09.693349) — Liu Z, et al., bioRxiv 2025 (Mouse, visual cortex V1, in vivo; Mouse, hippocampus CA1, in vivo) - [Movement-stabilized three-dimensional optical recordings of membrane potential changes and calcium dynamics in hippocampal CA1 dendrites](https://doi.org/10.1016/j.neuron.2026.01.004) — Gonzalez KC, et al., Neuron 2026 (Mouse, hippocampus CA1, dendrites and soma, in vivo) - [Kilohertz-rate two-photon voltage imaging of population dynamics in vivo](https://doi.org/10.64898/2025.12.29.696942) — Zhang M, et al., bioRxiv 2026 (Mouse, cortex, in vivo) - [Designer indicators for two-photon recording of subthreshold voltage dynamics](https://doi.org/10.1038/s41592-026-03043-8) — Land MA, Galdamez M, Villette V, Zhu J, Lu X, Marosi M, et al., Nature Methods 2026 (HEK293 cells, in vitro; Rat, cultured hippocampal neurons, in vitro; Mouse, visual cortex L2/3, in vivo) - [Optical constraints on two-photon voltage imaging](https://doi.org/10.1117/1.NPh.11.3.035007) — Brooks FP, et al., Neurophotonics 2024 (HEK293 cells, in vitro; Mouse, cortex, in vivo) - [Linking functional activity and connectivity of neuronal circuits via fast cross-layer all-optical physiology](https://doi.org/10.1016/j.celrep.2025.116646) — Liu C, et al., Cell Reports 2025 (Mouse, visual cortex V1 and somatosensory cortex S1, in vivo) - [A red-emitting, genetically encoded indicator for two-photon voltage recording in vivo](https://doi.org/10.64898/2026.06.01.726307) — Yang S, McDonald AJ, Lu X, Villette V, Hakam N, Galdamez M, et al., bioRxiv 2026 (Mouse, visual cortex L2/3, in vivo (JEDI-2P-Kv used as the in vivo benchmark for the red GEVI VADER1 under ULoVE and resonant-scanning 2P microscopy)) ## JEDI-3hyp JEDI-2P variant with two-photon voltage sensitivity shifted toward hyperpolarized potentials for detecting subthreshold fluctuations below resting membrane potential. - Category: VSD-cpGFP GEVI - Published: 2026-04-15 — [Nature Methods 2026](https://doi.org/10.1038/s41592-026-03043-8) - Derived from: [JEDI-2P](https://gevibench.org/gevi/jedi2p) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 501 nm, emission peak 519 nm (JEDI-3hyp) - Two-photon compatible: yes - Plasmid: [Addgene #246631](https://www.addgene.org/246631/) - Tags: cpGFP, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.41× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.2 / 2.1 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -51.5% (median of 2 measurements: −51.6%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.9% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 36.4% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 3.8 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.21 ms, τ_off 2.11 ms at 33°C — [Land 2026, Table 1](https://doi.org/10.1038/s41592-026-03043-8) #### ΔF/F per 100 mV - -51.5%, 2P — [Land 2026, Fig. 1h](https://doi.org/10.1038/s41592-026-03043-8) - -51.72%, 2P — [Land 2026, Ext. Fig. 1b](https://doi.org/10.1038/s41592-026-03043-8) #### ΔF/F per action potential - 36.4%, 2P — [Land 2026, Fig. 1j](https://doi.org/10.1038/s41592-026-03043-8) #### AP width (FWHM) - 6.3 ms at 20000 Hz sampling, HEK293A cells, whole-cell voltage clamp, in vitro (2-ms FWHM command AP waveform), 2P, 23°C — [Land 2026, Fig. 1k](https://doi.org/10.1038/s41592-026-03043-8) - 1.2 ms at 7000 Hz sampling, Mouse visual cortex, awake behaving, in vivo, soma-targeted JEDI3hyp-Kv (ULoVE 2P), 2P, 37°C — [Land 2026, Fig. 2d](https://doi.org/10.1038/s41592-026-03043-8) #### Brightness comparisons - 0.86× the brightness of JEDI-2P — [Land 2026, Fig. 1d](https://doi.org/10.1038/s41592-026-03043-8) - 1.25× the brightness of ASAP5 — [Land 2026, Ext. Fig. 1c](https://doi.org/10.1038/s41592-026-03043-8) #### Photobleaching - t75% = 83 s at 37 mW at sample plane (2P), 2P — [Land 2026, Fig. 1e](https://doi.org/10.1038/s41592-026-03043-8) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 91%; -100 mV: 65%; -80 mV: 20%; -70 mV: 0%; -60 mV: -18%; -50 mV: -28%; -30 mV: -40%; 0 mV: -45%; 30 mV: -52%; 50 mV: -55% — [Land 2026, Fig. 1h](https://doi.org/10.1038/s41592-026-03043-8) ### Research papers using JEDI-3hyp (1) - [Designer indicators for two-photon recording of subthreshold voltage dynamics](https://doi.org/10.1038/s41592-026-03043-8) — Land MA, Galdamez M, Villette V, Zhu J, Lu X, Marosi M, et al., Nature Methods 2026 (HEK293 cells, in vitro; Rat, cultured hippocampal neurons, in vitro; Mouse, visual cortex L2/3, in vivo; Mouse, hippocampus CA1 PV+ interneurons, in vivo; Mouse, cortex VIP+/SOM+ interneurons, in vivo) ## JEDI-3sub JEDI-2P variant engineered for two-photon detection of subthreshold voltage fluctuations with enhanced responsiveness across the physiological voltage range. - Category: VSD-cpGFP GEVI - Published: 2026-04-15 — [Nature Methods 2026](https://doi.org/10.1038/s41592-026-03043-8) - Derived from: [JEDI-2P](https://gevibench.org/gevi/jedi2p) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 501 nm, emission peak 519 nm (JEDI-3sub) - Two-photon compatible: yes - Plasmid: [Addgene #246619](https://www.addgene.org/246619/) - Tags: cpGFP, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.46× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.1 / 2.2 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -63.5% (median of 2 measurements: −61.9%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.3% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 42.8% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 3.9 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.06 ms, τ_off 2.23 ms at 33°C — [Land 2026, Table 1](https://doi.org/10.1038/s41592-026-03043-8) #### ΔF/F per 100 mV - -63.5%, 2P — [Land 2026, Fig. 1h](https://doi.org/10.1038/s41592-026-03043-8) - -60.26%, 2P — [Land 2026, Ext. Fig. 1b](https://doi.org/10.1038/s41592-026-03043-8) #### ΔF/F per action potential - 42.8%, 2P — [Land 2026, Fig. 1j](https://doi.org/10.1038/s41592-026-03043-8) #### AP width (FWHM) - 6.6 ms at 20000 Hz sampling, HEK293A cells, whole-cell voltage clamp, in vitro (2-ms FWHM command AP waveform), 2P, 23°C — [Land 2026, Fig. 1k](https://doi.org/10.1038/s41592-026-03043-8) - 1.3 ms at 1000 Hz sampling, Mouse visual cortex, awake behaving, in vivo, soma-targeted JEDI3sub-Kv (ULoVE 2P), 2P, 37°C — [Land 2026, Fig. 2d](https://doi.org/10.1038/s41592-026-03043-8) #### Brightness comparisons - 0.96× the brightness of JEDI-2P — [Land 2026, Fig. 1d](https://doi.org/10.1038/s41592-026-03043-8) - 1.39× the brightness of ASAP5 — [Land 2026, Ext. Fig. 1c](https://doi.org/10.1038/s41592-026-03043-8) #### Photobleaching - t75% = 53 s at 37 mW at sample plane (2P), 2P — [Land 2026, Fig. 1e](https://doi.org/10.1038/s41592-026-03043-8) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 58%; -100 mV: 25%; -80 mV: 10%; -70 mV: 0%; -60 mV: -15%; -50 mV: -28%; -30 mV: -45%; 0 mV: -55%; 30 mV: -60%; 50 mV: -62% — [Land 2026, Fig. 1h](https://doi.org/10.1038/s41592-026-03043-8) ### Research papers using JEDI-3sub (1) - [Designer indicators for two-photon recording of subthreshold voltage dynamics](https://doi.org/10.1038/s41592-026-03043-8) — Land MA, Galdamez M, Villette V, Zhu J, Lu X, Marosi M, et al., Nature Methods 2026 (HEK293 cells, in vitro; Rat, cultured hippocampal neurons, in vitro; Mouse, visual cortex L2/3, in vivo) ## LOTUS-V First bioluminescent FRET-based voltage indicator, enabling excitation-free ratiometric imaging. - Category: Bioluminescent GEVI - Published: 2017-02-13 — [Scientific Reports 2017](https://doi.org/10.1038/srep42398) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 455 nm, emission peak 528 nm (LOTUS-V) - Bioluminescent: emits light enzymatically, needs no excitation and does not photobleach - Plasmid: [Addgene #87127](https://www.addgene.org/87127/) - Tags: Bioluminescent, FRET, NanoLuc, Venus, Ci-VSP, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 129 / 103 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +21% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.14% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 2.8% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 11 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | bioluminescent (no photobleaching) | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 129.07 ms, τ_off 103.47 ms at 30°C — [Inagaki 2017, Fig. 2c](https://doi.org/10.1038/srep42398) - τ_on 119.12 ms, τ_off 73.17 ms at 23°C — [Inagaki 2019, Fig. 1C](https://doi.org/10.1038/s41598-019-43897-x) #### ΔF/F per 100 mV - +21% — [Inagaki 2017, Fig. 2b](https://doi.org/10.1038/srep42398) #### ΔF/F per action potential - 2.8% — [Inagaki 2019, Fig. 1D](https://doi.org/10.1038/s41598-019-43897-x) #### AP width (FWHM) - 11 ms at 1000 Hz sampling, Rat, hippocampal neurons, in vitro, 23°C — [Inagaki 2019, Fig. 1D](https://doi.org/10.1038/s41598-019-43897-x) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -107 mV: -5%; -70 mV: 0%; -37 mV: 5%; 4 mV: 13%; 30 mV: 21%; 63 mV: 26% — [Inagaki 2017, Fig. 2b](https://doi.org/10.1038/srep42398) ### Research papers using LOTUS-V (2) - [Genetically encoded bioluminescent voltage indicator for multi-purpose use in wide range of bioimaging](https://doi.org/10.1038/srep42398) — Inagaki S, Tsutsui H, Suzuki K, Agetsuma M, Arai Y, Jinno Y, Bai G, Daniels MJ, Okamura Y, Matsuda T, Nagai T, Scientific Reports 2017 (Rat, GH3 cells, in vitro; HEK293T cells; Xenopus oocytes; rat, PC12 cells; human, hiPSC-CMs, in vitro) - [Imaging local brain activity of multiple freely moving mice sharing the same environment](https://doi.org/10.1038/s41598-019-43897-x) — Inagaki S, Agetsuma M, Ohara S, Iijima T, Yokota H, Wazawa T, Arai Y, Nagai T, Scientific Reports 2019 (Mouse, visual cortex, in vivo; rat, hippocampal neurons, in vitro) ## MacQ-mCitrine Early opsin-fluorescent protein FRET voltage indicator, fusing the Mac rhodopsin to mCitrine. - Category: eFRET GEVI - Published: 2014-04-22 — [Nature Communications 2014](https://doi.org/10.1038/ncomms4674) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 515 nm, emission peak 529 nm (MacQ-mCitrine) - Two-photon compatible: no - Plasmid: [Addgene #48762](https://www.addgene.org/48762/) - Tags: Opsin, FRET ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.96× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 21 / 20 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -20% (median of 2 measurements: −19.7%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.2% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 4.8% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 10 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 2.6 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 5 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 20.5 ms, τ_off 19.6 ms at 22°C — [Gong 2014, Table S1](https://doi.org/10.1038/ncomms4674) #### ΔF/F per 100 mV - -20%, 1P — [Gong 2014, Fig. 3b](https://doi.org/10.1038/ncomms4674) - -19.49%, 1P — [Azimi 2019, Fig. 4C](https://doi.org/10.1073/pnas.1902443116) #### ΔF/F per action potential - 4.8%, 1P — [Gong 2014, Fig. 5d](https://doi.org/10.1038/ncomms4674) #### AP width (FWHM) - 10.2 ms at 440 Hz sampling, Cultured rat hippocampal neurons, in vitro, 1P — [Gong 2014, Fig. 5c](https://doi.org/10.1038/ncomms4674) #### Brightness comparisons - 3× the brightness of ArcLight — [Gong 2014, Main text](https://doi.org/10.1038/ncomms4674) #### Photobleaching - t75% = 17.5 s at 15 mW/mm², 1P — [Gong 2014, Table S1](https://doi.org/10.1038/ncomms4674) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 6%; -80 mV: 2%; -70 mV: 0%; -60 mV: -2%; -40 mV: -6%; -20 mV: -9%; 0 mV: -12%; 20 mV: -13%; 34 mV: -13% — [Gong 2014, Fig. 3b](https://doi.org/10.1038/ncomms4674) ### Research papers using MacQ-mCitrine (5) - [Imaging neural spiking in brain tissue using FRET-opsin protein voltage sensors](https://doi.org/10.1038/ncomms4674) — Gong Y, Wagner MJ, Zhong Li J, Schnitzer MJ, Nature Communications 2014 (HEK293 cells, cultured neurons, mouse brain slices and in vivo (Purkinje neurons)) - [High-speed recording of neural spikes in awake mice and flies with a fluorescent voltage sensor](https://doi.org/10.1126/science.aab0810) — Gong Y, et al., Science 2015 (HEK293 cells, cultured neurons, in vitro) - [Cell-Type-Specific Optical Recording of Membrane Voltage Dynamics in Freely Moving Mice](https://doi.org/10.1016/j.cell.2016.11.021) — Marshall JD, Li JZ, Zhang Y, Gong Y, St-Pierre F, Lin MZ, Schnitzer MJ, Cell 2016 (Mouse somatosensory cortex, striatum (D1/D2 MSNs), PV interneurons, in vivo freely moving) - [Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators](https://doi.org/10.7554/eLife.25690) — Chamberland S, et al., eLife 2017 (Drosophila visual neurons (L2), in vivo; rat hippocampal organotypic slices, in vitro) - [Rhodopsin-based voltage imaging tools for use in muscles and neurons of Caenorhabditis elegans](https://doi.org/10.1073/pnas.1902443116) — Azimi Hashemi N, et al., PNAS 2019 (C. elegans, pharyngeal and body wall muscles, in vivo) ## MacQ-mOrange2 Opsin-FRET voltage indicator pairing the Mac rhodopsin with mOrange2 as the FRET donor, the longer-wavelength sibling of MacQ-mCitrine introduced in the same study. - Category: eFRET GEVI - Published: 2014-04-22 — [Nature Communications 2014](https://doi.org/10.1038/ncomms4674) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 548 nm, emission peak 564 nm (MacQ-mOrange2) - Plasmid: [Addgene #48761](https://www.addgene.org/48761/) - Tags: Opsin, FRET, Red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.96× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 7.4 / 6.9 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -20% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.25% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 7.2% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 6.5 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 7.4 ms, τ_off 6.9 ms at 22°C — [Gong 2014, Table S1](https://doi.org/10.1038/ncomms4674) #### ΔF/F per 100 mV - -20%, 1P — [Gong 2014, Fig. 3b](https://doi.org/10.1038/ncomms4674) #### ΔF/F per action potential - 7.2%, 1P — [Gong 2014, Fig. 5d](https://doi.org/10.1038/ncomms4674) #### Brightness comparisons - 3× the brightness of ArcLight — [Gong 2014, Main text](https://doi.org/10.1038/ncomms4674) #### Photobleaching - t75% = 43.5 s (extrapolated) at 15 mW/mm², 1P — [Gong 2014, Table S1](https://doi.org/10.1038/ncomms4674) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 7%; -80 mV: 3%; -70 mV: 0%; -60 mV: -2%; -40 mV: -6%; -20 mV: -9%; 0 mV: -12%; 20 mV: -14%; 40 mV: -14% — [Gong 2014, Fig. 3b](https://doi.org/10.1038/ncomms4674) ### Research papers using MacQ-mOrange2 (1) - [Imaging neural spiking in brain tissue using FRET-opsin protein voltage sensors](https://doi.org/10.1038/ncomms4674) — Gong Y, Wagner MJ, Zhong Li J, Schnitzer MJ, Nature Communications 2014 (HEK293 cells, cultured neurons, mouse brain slices and in vivo (Purkinje neurons)) ## Marina Positive-going ArcLight variant created by directed evolution. - Category: VSD-single FP - Published: 2017-03-15 — [ACS Chemical Neuroscience 2017](https://doi.org/10.1021/acschemneuro.6b00234) - Derived from: [ArcLight](https://gevibench.org/gevi/arclight) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 488 nm, emission peak 511 nm (Marina) - Plasmid: [Addgene #74216](https://www.addgene.org/74216/) - Tags: Ci-VSP, Positive-going, pHluorin ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.44× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 29 / 33 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +29% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.25% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 1.4% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 49 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 4 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 29.2 ms, τ_off 32.7 ms at 37°C — [Platisa 2017, Fig. S2](https://doi.org/10.1021/acschemneuro.6b00234) #### ΔF/F per 100 mV - +29%, 1P — [Platisa 2017, Fig. 3B](https://doi.org/10.1021/acschemneuro.6b00234) #### ΔF/F per action potential - 1.4%, 1P — [Platisa 2017, Main text](https://doi.org/10.1021/acschemneuro.6b00234) #### Brightness comparisons - 0.677× the brightness of ArcLight — [Platisa 2017, Main text](https://doi.org/10.1021/acschemneuro.6b00234) #### Photobleaching - t75% = 272 s at 18 mW/mm², 1P — [Platisa 2017, Fig. 3C](https://doi.org/10.1021/acschemneuro.6b00234) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: -4%; -110 mV: -3%; -100 mV: -3%; -90 mV: -3%; -80 mV: -2%; -70 mV: 0%; -60 mV: 3%; -50 mV: 5%; -40 mV: 7%; -30 mV: 10%; -20 mV: 14%; -10 mV: 17%; 0 mV: 20%; 10 mV: 23%; 20 mV: 25%; 30 mV: 28% — [Platisa 2017, Fig. 3B](https://doi.org/10.1021/acschemneuro.6b00234) ### Research papers using Marina (4) - [Directed evolution of key residues in fluorescent protein inverses the polarity of voltage sensitivity in the genetically encoded indicator ArcLight](https://doi.org/10.1021/acschemneuro.6b00234) — Platisa J, Vasan G, Yang A, Pieribone VA, ACS Chemical Neuroscience 2017 (HEK293 cells and cultured mouse cortical neurons, in vitro) - [Generation of a genetically encoded voltage indicator MARINA reporter human iPS cell line using Cas9 (VULSCi002-A-2)](https://doi.org/10.1016/j.scr.2024.103628) — Petruskeviciu-te A, et al., Stem Cell Research 2024 (Human iPSC line with knock-in MARINA, in vitro) - [Stretch-induced endogenous electric fields drive directed collective cell migration in vivo](https://doi.org/10.1038/s41563-024-02060-2) — Ferreira F, et al., Nature Materials 2025 (Xenopus laevis neural crest cells, in vivo) - [In vivo Pirt-Marina voltage sensor imaging detects primary sensory neuron-specific voltage dynamics and neuronal plasticity changes](https://doi.org/10.1073/pnas.2416712122) — Zhang Y, et al., Proceedings of the National Academy of Sciences 2025 (Mouse, dorsal root ganglia, trigeminal ganglia, in vivo) ## Mermaid FRET-based GEVI using a VSD paired with coral-derived fluorescent proteins for ratiometric voltage. - Category: VSD-FRET GEVI - Published: 2008-07-11 — [Nature Methods 2008](https://doi.org/10.1038/nmeth.1235) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 483 nm, emission peak 564 nm (Mermaid) - Plasmid: [Addgene #53617](https://www.addgene.org/53617/) (Addgene #53617 is 'Chicken Mermaid S188' (deposited by V. Pieribone) — a chicken-codon-optimized derivative of the canonical Mermaid (Tsutsui et al. 2008), which does not appear to have its own Addgene deposit. Added as the closest available plasmid for this sensor; flagged as a variant, not the exact 2008 construct.) - Tags: Ci-VSP, FRET, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.29× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 10 / 19 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +40% (median of 2 measurements: +26.4%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.25% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 1.6% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 4.1 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 9 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 8 ms, τ_off 15 ms at 33°C — [Tsutsui 2008, Fig. 1f](https://doi.org/10.1038/nmeth.1235) - τ_on 12 ms, τ_off 23 ms at 35-37°C — [Barnett 2012, Fig. 5B](https://doi.org/10.1371/journal.pone.0043454) #### ΔF/F per 100 mV - +40%, 1P — [Tsutsui 2008, Fig. 1e](https://doi.org/10.1038/nmeth.1235) - +12.9%, 1P — [Mutoh 2009, Table 1](https://doi.org/10.1371/journal.pone.0004555) #### ΔF/F per action potential - 1.6%, 1P — [Tsutsui 2008, Table S1](https://doi.org/10.1038/nmeth.1235) #### Brightness comparisons - 1.286× the brightness of EGFP — [Tsutsui 2008, Main text](https://doi.org/10.1038/nmeth.1235) #### Photobleaching - t75% = 33 s, 1P — [Tsutsui 2008, Fig. S2a](https://doi.org/10.1038/nmeth.1235) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: -5%; -100 mV: -5%; -80 mV: -3%; -70 mV: 0%; -60 mV: 2%; -40 mV: 16%; -20 mV: 26%; 0 mV: 33%; 20 mV: 36%; 40 mV: 37% — [Tsutsui 2008, Fig. 1e](https://doi.org/10.1038/nmeth.1235) ### Research papers using Mermaid (9) - [Improving membrane voltage measurements using FRET with new fluorescent proteins](https://doi.org/10.1038/nmeth.1235) — Tsutsui H, Karasawa S, Okamura Y, Miyawaki A, Nature Methods 2008 (HEK293 cells, Neuro2A cells, rat cortical neurons, Xenopus oocytes, in vitro) - [Visualizing voltage dynamics in zebrafish heart](https://doi.org/10.1113/jphysiol.2010.189126) — Tsutsui H, et al., The Journal of Physiology 2010 (Zebrafish, heart, in vivo) - [Optical action potential screening on adult ventricular myocytes as an alternative QT-screen](https://doi.org/10.1159/000327954) — Tian Q, et al., Cellular Physiology and Biochemistry 2011 (Rat, ventricular myocytes, in vitro) - [Neural coding in a single sensory neuron controlling opposite seeking behaviours in Caenorhabditis elegans](https://doi.org/10.1038/ncomms1352) — Kuhara A, et al., Nature Communications 2011 (C. elegans, in vivo) - [Rapid evaluation of a protein-based voltage probe using a field-induced membrane potential change](https://doi.org/10.1016/j.bbamem.2014.03.002) — Tsutsui H, et al., Biochimica et Biophysica Acta 2014 (HEK293 cells, in vitro) - [INaP selective inhibition reverts precocious inter- and motorneurons hyperexcitability in the Sod1-G93R zebrafish ALS model](https://doi.org/10.1038/srep24515) — Benedetti L, et al., Scientific Reports 2016 (Zebrafish, spinal motor neurons, in vivo) - [Biosensing Motor Neuron Membrane Potential in Live Zebrafish Embryos](https://doi.org/10.3791/55297) — Benedetti L, et al., Journal of Visualized Experiments 2017 (Zebrafish, motor neurons, in vivo) - [Tracking the sarcoplasmic reticulum membrane voltage in muscle with a FRET biosensor](https://doi.org/10.1085/jgp.201812035) — Sanchez C, et al., The Journal of General Physiology 2018 (Mouse, skeletal muscle fibers, in vitro) - [Use of FRET-Sensor 'Mermaid' to Detect Subtle Changes in Membrane Potential of Primary Mouse PASMCs](https://doi.org/10.3390/cells13121070) — Dartsch RC, et al., Cells 2024 (Mouse, pulmonary arterial smooth muscle cells, in vitro) ## Mermaid2 Improved CFP/YFP FRET variant of Mermaid engineered for larger ratiometric response and submillisecond activation, enabling single-trial detection of action potential trains up to 150 Hz. - Category: VSD-FRET GEVI - Published: 2013-08-09 — [J. Physiol. 2013](https://doi.org/10.1113/jphysiol.2013.257048) - Derived from: [Mermaid](https://gevibench.org/gevi/mermaid) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 435 nm, emission peak 529 nm (Mermaid2) - Tags: Ci-VSP, FRET, CFP/YFP, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.5 / 10 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +48.5% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.35% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 2.57% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 3.46 ms, τ_off 10.3 ms at 33°C — [Tsutsui 2013, Fig. 4C](https://doi.org/10.1113/jphysiol.2013.257048) #### ΔF/F per 100 mV - +48.5%, 1P — [Tsutsui 2013, Fig. 4B](https://doi.org/10.1113/jphysiol.2013.257048) #### ΔF/F per action potential - 2.57%, 1P — [Tsutsui 2013, Fig. 6B](https://doi.org/10.1113/jphysiol.2013.257048) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -90 mV: -5%; -80 mV: -3%; -70 mV: 0%; -60 mV: 4%; -50 mV: 9%; -40 mV: 15%; -30 mV: 21%; -20 mV: 27%; -10 mV: 32%; 0 mV: 37%; 10 mV: 40%; 20 mV: 43%; 30 mV: 45%; 40 mV: 46%; 50 mV: 47% — [Tsutsui 2013, Fig. 4B](https://doi.org/10.1113/jphysiol.2013.257048) ### Research papers using Mermaid2 (1) - [Improved detection of electrical activity with a voltage probe based on a voltage-sensing phosphatase](https://doi.org/10.1113/jphysiol.2013.257048) — Tsutsui H, Jinno Y, Tomita A, Niino Y, Yamada Y, Mikoshiba K, Miyawaki A, Okamura Y, The Journal of Physiology 2013 (HEK293 cells, rat hippocampal neurons, in vitro; mouse auditory cortex, in vivo (1P); Xenopus oocytes, in vitro) ## nirButterfly Near-infrared VSFP-Butterfly variant using bacterial phytochrome-derived fluorescent proteins. - Category: VSD-FRET GEVI - Published: 2020-11-04 — [ACS Chemical Neuroscience 2020](https://dx.doi.org/10.1021/acschemneuro.0c00046) - Derived from: [VSFP-Butterfly](https://gevibench.org/gevi/vsfpbutterfly) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 644 nm, emission peak 670 nm (nirButterfly) - Plasmid: [Addgene #136590](https://www.addgene.org/136590/) - Tags: Ci-VSP, NIR FP, FRET, Biliverdin ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.04× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.2 / 2.1 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -9.8% (median of 2 measurements: −10%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.1% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | -6% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 1.0 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.16 ms, τ_off 2.13 ms at 23°C — [Monakhov 2020, Fig. 1g](https://doi.org/10.1021/acschemneuro.0c00046) #### ΔF/F per 100 mV - -9.8%, 1P — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - +10.2%, 1P — [Monakhov 2020, Main text](https://doi.org/10.1021/acschemneuro.0c00046) #### ΔF/F per action potential - -6%, 1P — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) #### Brightness comparisons - 486× the brightness of Arch — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 7× the brightness of Archon1 — [Song 2024, Fig. 2b](https://doi.org/10.1117/1.NPh.11.2.024201) - 3.17× the brightness of SomArchon — [Monakhov 2020, Fig. S2](https://doi.org/10.1021/acschemneuro.0c00046) #### Photobleaching - t75% = 139 s at 44 mW/mm², 1P — [Monakhov 2020, Fig. S2](https://doi.org/10.1021/acschemneuro.0c00046) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 3%; -80 mV: 1%; -70 mV: 0%; -60 mV: -1%; -40 mV: -4%; -20 mV: -6%; 0 mV: -7%; 20 mV: -9%; 40 mV: -10%; 60 mV: -11% — [Monakhov 2020, Fig. 3b (NIR GEVIb)](https://doi.org/10.1021/acschemneuro.0c00046) ### Research papers using nirButterfly (2) - [Screening and Cellular Characterization of Genetically Encoded Voltage Indicators Based on Near-Infrared Fluorescent Proteins](https://doi.org/10.1021/acschemneuro.0c00046) — Monakhov MV, Matlashov ME, Colavita M, Song C, Shcherbakova DM, Antic SD, Verkhusha VV, Knöpfel T, ACS Chemical Neuroscience 2020 (HEK293 cells and mouse cortical/hippocampal neurons, in vitro) - [Characterization of two near-infrared genetically encoded voltage indicators](https://doi.org/10.1117/1.NPh.11.2.024201) — Song C, Matlashov ME, Shcherbakova DM, et al., Neurophotonics 2024 (Mouse, hippocampal CA3 slices, in vitro) ## NovArch Photoactivatable archaerhodopsin-derived indicator whose near-infrared fluorescence is reversibly enhanced by one-photon blue or two-photon near-infrared excitation, enabling optically sectioned voltage imaging in tissue. - Category: Opsin GEVI - Published: 2021-05-07 — [Science Advances 2021](https://doi.org/10.1126/sciadv.abe3216) - Derived from: [paQuasAr3](https://gevibench.org/gevi/quasar3) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 620 nm, emission peak 715 nm (NovArch) - Plasmid: [Addgene #153193](https://www.addgene.org/153193/) - Tags: Archaerhodopsin, Far-red, Photoactivated, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.01× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.3 / 5.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +41% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.41% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 28% (median of 2 measurements: 28%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 5.9 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 33.6 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 3.31 ms, τ_off 5.65 ms at 25°C — [Chien 2021, Fig. 3F](https://doi.org/10.1126/sciadv.abe3216) #### ΔF/F per 100 mV - +41%, 1P — [Chien 2021, Fig. 3E](https://doi.org/10.1126/sciadv.abe3216) #### ΔF/F per mV (subthreshold) - 0.41%/mV (Derived from the whole-range 41% per 100 mV voltage sensitivity under red-only illumination (Fig. 3E); the paper reports no dedicated -90 to -50 mV subthreshold slope, but the F-V is near-linear so the average slope approximates the subthreshold slope.) — [Chien 2021, Fig. 3E](https://doi.org/10.1126/sciadv.abe3216) #### ΔF/F per action potential - 28%, 1P — [Chien 2021, Fig. 4B](https://doi.org/10.1126/sciadv.abe3216) - 79%, 2P — [Chien 2021, Fig. 4B](https://doi.org/10.1126/sciadv.abe3216) #### AP width (FWHM) - 5.9 ms at 1000 Hz sampling, Mouse L5 cortical pyramidal neuron, acute brain slice, 1P, 23°C — [Chien 2021, Fig. 7D](https://doi.org/10.1126/sciadv.abe3216) #### Brightness comparisons - 3× the brightness of Archon1 — [Chien 2021, Fig. S1C](https://doi.org/10.1126/sciadv.abe3216) #### Photobleaching - t75% = 144 s at 1400 mW/mm² (640 nm) + 220 mW/mm² (488 nm), 1P — [Chien 2021, Fig. S4C](https://doi.org/10.1126/sciadv.abe3216) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -13%; -70 mV: 0%; -60 mV: 3%; -20 mV: 20%; 0 mV: 28%; 30 mV: 41%; 60 mV: 46%; 100 mV: 57% — [Chien 2021, Fig. 3E](https://doi.org/10.1126/sciadv.abe3216) ### Research papers using NovArch (2) - [Photoactivated voltage imaging in tissue with an archaerhodopsin-derived reporter](https://doi.org/10.1126/sciadv.abe3216) — Chien MP, Brinks D, Testa-Silva G, Tian H, Brooks FP III, Adam Y, Bloxham W, Gmeiner B, Kheifets S, Cohen AE, Science Advances 2021 (HEK293T cells, in vitro; cultured rat hippocampal neurons, in vitro; mouse L5 cortical pyramidal neurons, acute brain slices; mouse hippocampus CA1, in vivo) - [Optical Switching Between Long-lived States of Opsin Transmembrane Voltage Sensors](https://doi.org/10.1111/php.13428) — Mei G, Cavini CM, Mamaeva N, Wang P, DeGrip WJ, Rothschild KJ, Photochemistry and Photobiology 2021 (Purified NovArch protein reconstituted in membrane vesicles (FT-Raman and UV-vis spectroscopy of the photocycle); also QuasAr2) ## pAce Reverse-polarity variant of Ace-mNeon2 whose fluorescence increases during depolarization, enabling dual-polarity multiplexed voltage imaging in a single color channel. - Category: eFRET GEVI - Published: 2022-11-04 — [Science 2022](https://doi.org/10.1126/science.abm8797) - Derived from: [Ace2N-mNeon2](https://gevibench.org/gevi/ace2n-mneon2) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 506 nm, emission peak 517 nm (pAce) - Two-photon compatible: yes - Plasmid: [Addgene #195523](https://www.addgene.org/195523/) - Tags: Ace opsin, mNeon, Green, Positive ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 2.40× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 0.69 / 1.2 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +30.5% (median of 2 measurements: +35.8%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.33% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 10.7% (median of 3 measurements: 19.9%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4.3 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 32 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 7 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 0.69 ms, τ_off 1.18 ms at 22°C — [Kannan 2022, Table S1](https://doi.org/10.1126/science.abm8797) #### ΔF/F per 100 mV - +30.5%, 1P — [Kannan 2022, Table S1](https://doi.org/10.1126/science.abm8797) - +41%, 1P — [Grimm 2026, Fig. 1C(i)](https://doi.org/10.1016/j.neuron.2025.12.014) #### ΔF/F per action potential - 10.7%, 1P — [Kannan 2022, Fig. 1I](https://doi.org/10.1126/science.abm8797) - 43%, 1P — [Grimm 2026, Fig. 1G(ii)](https://doi.org/10.1016/j.neuron.2025.12.014) - 19.9%, 1P — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) #### AP width (FWHM) - 2.9 ms at 400 Hz sampling, Mouse, V1 VIP+ interneurons, awake, in vivo, 1P, 37°C — [Kannan 2022, Fig. 1I](https://doi.org/10.1126/science.abm8797) - 5.7 ms at 1000 Hz sampling, Mouse, primary hippocampal neurons, in vitro, 1P, 22°C — [Zhang 2025, Fig. 1j](https://doi.org/10.1101/2025.05.30.657123) #### Brightness comparisons - 0.7× the brightness of Ace2N-mNeon — [Kannan 2022, Fig. S11A](https://doi.org/10.1126/science.abm8797) - 28× the brightness of ASAP4e — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) - 0.7692307692307692× the brightness of ElectraON — [Zhang 2025, Fig. 1e](https://doi.org/10.1101/2025.05.30.657123) - 2.380952380952381× the brightness of Jarvis — [Grimm 2026, Fig. 1C](https://doi.org/10.1016/j.neuron.2025.12.014) #### Photobleaching - t75% = 81 s, 1P — [Grimm 2026, Fig. 1F](https://doi.org/10.1016/j.neuron.2025.12.014) - t75% = 636 s at 5 mW/mm², 1P — [Zhang 2025, Fig. S4h](https://doi.org/10.1101/2025.05.30.657123) - t75% = 68 s, 1P — [Kannan 2022, Fig. S11B](https://doi.org/10.1126/science.abm8797) - t75% = 325 s, 1P — [Zhang 2025, Fig. 1h](https://doi.org/10.1101/2025.05.30.657123) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -150 mV: -23%; -130 mV: -19%; -110 mV: -14%; -90 mV: -8%; -70 mV: 0%; -50 mV: 5%; -30 mV: 14%; -10 mV: 20%; 10 mV: 25%; 30 mV: 31%; 50 mV: 36% — [Kannan 2022, Fig. 1D](https://doi.org/10.1126/science.abm8797) ### Research papers using pAce (7) - [Dual-polarity voltage imaging of the concurrent dynamics of multiple neuron types](https://doi.org/10.1126/science.abm8797) — Kannan M, Vasan G, Haziza S, Huang C, Chrapkiewicz R, Luo J, Cardin JA, Schnitzer MJ, Pieribone VA, Science 2022 (Mouse, visual cortex, in vivo; mouse, hippocampus CA1, in vivo; Drosophila, MBON and PPL1 neurons, in vivo; HEK cells, in vitro) - [Wide-field fluorescence lifetime imaging of neuron spiking and subthreshold activity in vivo](https://doi.org/10.1126/science.adf9725) — Bowman AJ, Huang C, Schnitzer MJ, Kasevich MA, Science 2023 (Drosophila, in vivo) - [Dopamine-mediated interactions between short- and long-term memory dynamics](https://doi.org/10.1038/s41586-024-07819-w) — Huang C, Luo J, Woo SJ, Roitman LA, Li J, Pieribone VA, Kannan M, Vasan G, Schnitzer MJ, Nature 2024 (Drosophila, mushroom body neurons, in vivo) - [Imaging high-frequency voltage dynamics in multiple neuron classes of behaving mammals](https://doi.org/10.1016/j.cell.2025.06.028) — Haziza S, Chrapkiewicz R, Zhang Y, Kruzhilin V, Li J, Delamare G, Swanson R, Buzsáki G, Kannan M, Vasan G, Lin MZ, Zeng H, Daigle T, Schnitzer MJ, Cell 2025 (Mouse, visual cortex and hippocampus, in vivo) - [High-speed voltage imaging of action potentials in molecular layer interneurons reveals sensory-driven synchrony that augments movement](https://doi.org/10.1016/j.celrep.2025.116148) — Brown ST, Holla MR, Land MA, Yang S, McDonald AJ, St-Pierre F, Raman IM, Cell Reports 2025 (Mouse, cerebellar cortex, in vivo) - [Two-photon voltage imaging with rhodopsin-based sensors](https://doi.org/10.1016/j.neuron.2025.12.014) — Grimm C, Sims RR, Tanese D, Lafirdeen ASM, Bendifallah I, Chan CY, Faini G, Putti E, Del Bene F, Papagiakoumou E, Emiliani V, Neuron 2026 (Mouse cortical neurons, in vitro; zebrafish larvae, in vivo) - [Bright and Photostable Voltage Sensors Derived from mBaoJin](https://doi.org/10.1101/2025.05.30.657123) — Zhang H, Zhou S, Kuzmicheva TP, Subach OM, Grimm C, Eom M, Baror-Sebban S, Adam Y, Yoon YG, Emilliani V, Subach FV, Piatkevich KD, bioRxiv 2025 (HeLa cells; Mouse, primary hippocampal neurons, in vitro (benchmark comparison against ElectraON/ElectraOFF)) ## pAceR Reverse-polarity red variant of VARNAM2 that brightens upon depolarization, enabling dual-polarity multiplexed voltage imaging alongside negative-going sensors in the same color channel. - Category: eFRET GEVI - Published: 2022-11-04 — [Science 2022](https://doi.org/10.1126/science.abm8797) - Derived from: [VARNAM2](https://gevibench.org/gevi/varnam2) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 558 nm, emission peak 592 nm (pAceR) - Plasmid: [Addgene #195534](https://www.addgene.org/195534/) - Tags: Ace opsin, mRuby3, Red, FRET, Positive ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.59× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.8 / 4.1 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +27.8% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.2% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 3.2% (median of 2 measurements: 4.9%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 2.7 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 41 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 3.78 ms, τ_off 4.13 ms at 22°C — [Kannan 2022, Table S1](https://doi.org/10.1126/science.abm8797) #### ΔF/F per 100 mV - +27.8%, 1P — [Kannan 2022, Table S1](https://doi.org/10.1126/science.abm8797) #### ΔF/F per action potential - 3.2%, 1P — [Kannan 2022, Fig. 1I](https://doi.org/10.1126/science.abm8797) - 6.6%, 1P — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) #### AP width (FWHM) - 2.7 ms at 400 Hz sampling, Mouse, V1 VIP+ interneurons, awake, in vivo, 1P, 37°C — [Kannan 2022, Fig. 1I](https://doi.org/10.1126/science.abm8797) #### Brightness comparisons - 0.7× the brightness of VARNAM2 — [Kannan 2022, Fig. S11A](https://doi.org/10.1126/science.abm8797) #### Photobleaching - t75% = 162 s, 1P — [Kannan 2022, Fig. S11B](https://doi.org/10.1126/science.abm8797) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -150 mV: -18%; -130 mV: -15%; -110 mV: -10%; -90 mV: -5%; -70 mV: 0%; -50 mV: 3%; -30 mV: 7%; -10 mV: 14%; 10 mV: 20%; 30 mV: 28%; 50 mV: 33% — [Kannan 2022, Fig. 1D](https://doi.org/10.1126/science.abm8797) ### Research papers using pAceR (2) - [Dual-polarity voltage imaging of the concurrent dynamics of multiple neuron types](https://doi.org/10.1126/science.abm8797) — Kannan M, Vasan G, Haziza S, Huang C, Chrapkiewicz R, Luo J, Cardin JA, Schnitzer MJ, Pieribone VA, Science 2022 (HEK cells, in vitro; mouse hippocampus CA1, in vivo; Drosophila PPL1 dopaminergic neurons, in vivo) - [Positive-going hybrid indicators for voltage imaging in excitable cells and tissues](https://doi.org/10.1126/sciadv.ads1807) — Liu S, et al., Science Advances 2025 (Cultured rat hippocampal neurons; pAceR measured (6.6 ± 0.5% ΔF/F0 per AP, n=5, Table S2) as a positive-going reference, 1P epifluorescence) ## Pado Based on a proton channel VSD, uniquely capable of reporting membrane potential, pH, and gap junction in a single construct. - Category: VSD-single FP - Published: 2016-04-04 — [Scientific Reports 2016](https://doi.org/10.1038/srep23865) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 488 nm, emission peak 511 nm (Pado) - Tags: pHluorin, Hv-VSD ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 93 / 10 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -5% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.05% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 93 ms, τ_off 10 ms at 35°C — [Kang 2016, Fig. 5b](https://doi.org/10.1038/srep23865) #### ΔF/F per 100 mV - -5%, 1P — [Kang 2016, Fig. 2a](https://doi.org/10.1038/srep23865) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -70 mV: 0%; 30 mV: -5%; 130 mV: -10% — [Kang 2016, Fig. 2a](https://doi.org/10.1038/srep23865) ### Research papers using Pado (1) - [Pado, a fluorescent protein with proton channel activity can optically monitor membrane potential, intracellular pH, and map gap junctions](https://doi.org/10.1038/srep23865) — Kang BE, Baker BJ, Scientific Reports 2016 (HEK293 cells, in vitro) ## paQuasAr3 Photoactivatable QuasAr3 variant that can be selectively activated. - Category: Opsin GEVI - Published: 2019-05-01 — [Nature 2019](https://doi.org/10.1038/s41586-019-1166-7) - Derived from: [QuasAr2](https://gevibench.org/gevi/quasar2) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 590 nm, emission peak 715 nm (paQuasAr3) - Plasmid: [Addgene #107703](https://www.addgene.org/107703/) - Tags: Archaerhodopsin, Far-red, Photoactivated ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.0012× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 8.1 / 4.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +40% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.4% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 23.5% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 1.8 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 3.3 h | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 12 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 9.3 ms, τ_off 5.4 ms at 34°C — [Adam 2019, Ext. Fig. 3e](https://doi.org/10.1038/s41586-019-1166-7) - τ_on 6.8 ms, τ_off 3.9 ms at 34°C — [Adam 2019, Ext. Fig. 3e](https://doi.org/10.1038/s41586-019-1166-7) #### ΔF/F per 100 mV - +40%, 1P — [Adam 2019, Fig. 1g](https://doi.org/10.1038/s41586-019-1166-7) #### ΔF/F per mV (subthreshold) - 0.4%/mV (0.4%/mV derived from 40 +/- 1.7% per 100 mV voltage sensitivity measured in acute brain slices (Fig. 1g). SNR = 0.93 +/- 0.07 per mV in 1 kHz bandwidth.) — [Adam 2019, Fig. 1g](https://doi.org/10.1038/s41586-019-1166-7) #### ΔF/F per action potential - 23.5%, 1P — [Piatkevich 2019, Ext. Fig. 5c](https://doi.org/10.1038/s41586-019-1641-1) #### AP width (FWHM) - 1.8 ms at 1000 Hz sampling, Mouse, hippocampus CA1 oriens interneuron, in vivo, 1P, 37°C — [Adam 2019, Fig. 1i](https://doi.org/10.1038/s41586-019-1166-7) #### Brightness comparisons - 2× the brightness of QuasAr2 — [Adam 2019, Ext. Fig. 3f](https://doi.org/10.1038/s41586-019-1166-7) - 0.0017985611510791368× the brightness of ASAP3 — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) #### Photobleaching - t75% = 98 s at 12000 mW/mm², 1P — [Adam 2019, Ext. Fig. 5a](https://doi.org/10.1038/s41586-019-1166-7) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -75 mV: 0%; -50 mV: 12%; -25 mV: 23%; 0 mV: 32%; 25 mV: 42%; 50 mV: 52%; 75 mV: 65% — [Adam 2019, Ext. Fig. 3d](https://doi.org/10.1038/s41586-019-1166-7) ### Research papers using paQuasAr3 (12) - [Voltage imaging and optogenetics reveal behaviour-dependent changes in hippocampal dynamics](https://doi.org/10.1038/s41586-019-1166-7) — Adam Y, Kim JJ, Lou S, Zhao Y, Xie ME, Brinks D, Wu H, Mostajo-Radji MA, Kheifets S, Parot V, Chettih S, Williams KJ, Gmeiner B, Farhi SL, Madisen L, Buchanan EK, Kinsella I, Zhou D, Paninski L, Harvey CD, Zeng H, Arlotta P, Campbell RE, Cohen AE, Nature 2019 (Mouse, hippocampus CA1 and olfactory bulb, in vivo (awake behaving); HEK293T cells and acute brain slices) - [Population imaging of neural activity in awake behaving mice](https://doi.org/10.1038/s41586-019-1641-1) — Piatkevich KD, Bensussen S, Tseng HA, Shroff SN, Lopez-Huerta VG, Park D, Jung EE, Shemesh OA, Straub C, Gritton HJ, Romano MF, Costa E, Sabatini BL, Fu Z, Boyden ES, Han X, Nature 2019 (Mouse, cortex L2/3 and hippocampus, acute slices and in vivo (paQuasAr3-s used as a comparison GEVI for SomArchon)) - [All-optical electrophysiology reveals the role of lateral inhibition in sensory processing in cortical layer 1](https://doi.org/10.1016/j.cell.2019.12.025) — Fan LZ, et al., Cell 2020 (Mouse, barrel cortex L1 interneurons, in vivo (awake behaving)) - [Scalable measurements of intrinsic excitability in human iPS cell-derived excitatory neurons using all-optical electrophysiology](https://doi.org/10.1007/s11064-018-2694-5) — Williams LA, et al., Neurochemical Research 2019 (Human iPSC-derived excitatory cortical neurons, in vitro) - [Photoactivated voltage imaging in tissue with an archaerhodopsin-derived reporter](https://doi.org/10.1126/sciadv.abe3216) — Chien MP, et al., Science Advances 2021 (Mouse, hippocampus acute slices and CA1 in vivo) - [High-fidelity estimates of spikes and subthreshold waveforms from 1-photon voltage imaging in vivo](https://doi.org/10.1016/j.celrep.2021.108954) — Xie ME, et al., Cell Reports 2021 (Mouse, hippocampus CA1, in vivo; zebrafish spinal cord) - [Linearly polarized excitation enhances signals from fluorescent voltage indicators](https://doi.org/10.1016/j.bpj.2021.10.028) — Bloxham W, et al., Biophysical Journal 2021 (HEK293 cells and cultured rat hippocampal neurons) - [Video-based pooled screening yields improved far-red genetically encoded voltage indicators](https://doi.org/10.1038/s41592-022-01743-5) — Tian H, et al., Nature Methods 2023 (HEK293 cells, cultured neurons, mouse cortex and hippocampus in vivo) - [Statistically unbiased prediction enables accurate denoising of voltage imaging data](https://doi.org/10.1038/s41592-023-02005-8) — Eom M, et al., Nature Methods 2023 (Mouse, brain tissue (denoising benchmark on paQuasAr3-s datasets)) - [Mechanism of sensory perception unveiled by simultaneous measurement of membrane voltage and intracellular calcium](https://doi.org/10.1038/s42003-024-06778-2) — Tokunaga T, et al., Communications Biology 2024 (C. elegans, AWA olfactory neurons (simultaneous voltage + calcium imaging)) - [Optical constraints on two-photon voltage imaging](https://doi.org/10.1117/1.NPh.11.3.035007) — Brooks FP III, et al., Neurophotonics 2024 (Cultured neurons and mouse brain (1P/2P GEVI characterization)) - [Robust self-supervised denoising of voltage imaging data using CellMincer](https://doi.org/10.1038/s44303-024-00055-x) — Wang B, et al., npj Imaging 2024 (Primary neurons and iPSC-derived neurons, in vitro) ## Positron Positive-going Voltron variant with inverted fluorescence polarity. - Category: Chemigenetic GEVI - Published: 2020-07-10 — [Nature Communications 2020](https://doi.org/10.1038/s41467-020-17322-1) - Derived from: [Voltron](https://gevibench.org/gevi/voltron) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 534 nm, emission peak 554 nm (Positron (JF525)) - Plasmid: [Addgene #129253](https://www.addgene.org/129253/) - Tags: Ace opsin, HaloTag, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.56× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.4 / 4.3 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +23% (median of 4 measurements: +17.4%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.25% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 5.9% (median of 2 measurements: 6.2%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 48 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 3 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 3.39 ms, τ_off 4.28 ms at 25°C — [Abdelfattah 2020, Table S1](https://doi.org/10.1038/s41467-020-17322-1) - τ_on 11.27 ms, τ_off 10.76 ms at 25°C — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) #### ΔF/F per 100 mV - +23%, 1P, dye JF525 — [Abdelfattah 2020, Fig. 2a](https://doi.org/10.1038/s41467-020-17322-1) - +20%, 1P, dye JF525 — [Abdelfattah 2020, Fig. S4](https://doi.org/10.1038/s41467-020-17322-1) - +14.7%, 1P, dye JF525 — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) - +12%, 1P, dye JF525 — [Hasseman 2022, Fig. 1](https://doi.org/10.25378/janelia.21534411) #### ΔF/F per action potential - 5.9%, 1P, dye JF525 — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) - 6.5%, 1P, dye JF525 — [Hasseman 2022, Fig. 2](https://doi.org/10.25378/janelia.21534411) #### Brightness comparisons - 0.59× the brightness of Voltron — [Abdelfattah 2020, Fig. 2b](https://doi.org/10.1038/s41467-020-17322-1) - 3.5× the brightness of ASAP4e — [Lee 2024, Table S4](https://doi.org/10.1101/2024.06.21.599617) #### Photobleaching - t75% = 96 s at 50 mW/mm², 1P — [Liu 2025, Fig. S7](https://doi.org/10.1126/sciadv.ads1807) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -110 mV: -8%; -90 mV: -5%; -70 mV: 0%; -50 mV: 5%; -30 mV: 9%; -10 mV: 12%; 10 mV: 16%; 30 mV: 20%; 50 mV: 24% — [Abdelfattah 2020, Fig. 2a](https://doi.org/10.1038/s41467-020-17322-1) ### Research papers using Positron (3) - [A general approach to engineer positive-going eFRET voltage indicators](https://doi.org/10.1038/s41467-020-17322-1) — Abdelfattah AS, et al., Nature Communications 2020 (Rat, hippocampal neurons, in vitro; Zebrafish, forebrain, in vivo) - [Positive-going hybrid indicators for voltage imaging in excitable cells and tissues](https://doi.org/10.1126/sciadv.ads1807) — Liu S, et al., Science Advances 2025 (Rat, hippocampal neurons, in vitro) - [Improving positively tuned voltage indicators for faster kinetics and higher contrast](https://doi.org/10.1101/2024.06.21.599617) — Lee S, Zhang G, Hao YA, et al., bioRxiv 2024 (Rat, cortical neurons, in vitro) ## Positron2 Positive-going Ace2N-HaloTag variant optimized for stronger spike and subthreshold responses in cultured neurons. - Category: Chemigenetic GEVI - Published: 2022-11-10 — [Janelia Figshare 2022](https://doi.org/10.25378/janelia.21534411) - Derived from: [Positron](https://gevibench.org/gevi/positron); also related to [pAce](https://gevibench.org/gevi/pace) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 534 nm, emission peak 554 nm (Positron2 (JF525)) - Plasmid: [Addgene #239079](https://www.addgene.org/239079/) - Tags: Ace opsin, HaloTag, Positive-going, JF525 ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | — | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +37% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.38% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 15% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### ΔF/F per 100 mV - +37%, 1P, dye JF525 — [Hasseman 2022, Fig. 1](https://doi.org/10.25378/janelia.21534411) #### ΔF/F per action potential - 15%, 1P, dye JF525 — [Hasseman 2022, Fig. 2](https://doi.org/10.25378/janelia.21534411) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -110 mV: -12%; -90 mV: -7%; -70 mV: 0%; -50 mV: 8%; -30 mV: 16%; -10 mV: 24%; 10 mV: 32%; 30 mV: 37%; 50 mV: 41% — [Hasseman 2022, Fig. 1](https://doi.org/10.25378/janelia.21534411) ### Research papers using Positron2 (1) - [Optimization of genetically encoded voltage and calcium indicators for in vivo imaging](https://doi.org/10.25378/janelia.21534411) — Hasseman J, Abdelfattah AS, Arthur B, et al., Janelia Figshare 2022 (Rat, cortical/hippocampal neurons, in vitro) ## PROPS First microbial opsin-based voltage indicator, though only functional in bacteria and extremely dim. - Category: Opsin GEVI - Published: 2011-07-15 — [Science 2011](https://doi.org/10.1126/science.1204763) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 555 nm, emission peak 710 nm (PROPS) - Plasmid: [Addgene #33780](https://www.addgene.org/33780/) - Tags: NIR FP, Microbial, Bacteria-only ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 4.7 / 4.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +150% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.8% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 4 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 4.7 ms, τ_off 4.7 ms at 25°C — [Kralj 2011, Fig. 1D](https://doi.org/10.1126/science.1204763) #### ΔF/F per 100 mV - +150%, 1P — [Kralj 2011, Fig. 1C](https://doi.org/10.1126/science.1204763) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -150 mV: -47%; -130 mV: -41%; -110 mV: -29%; -90 mV: -13%; -70 mV: 0%; -50 mV: 19%; -30 mV: 42%; -10 mV: 55%; 10 mV: 75%; 30 mV: 91%; 50 mV: 100%; 70 mV: 112% — [Kralj 2011, Fig. 1C](https://doi.org/10.1126/science.1204763) ### Research papers using PROPS (4) - [Electrical spiking in Escherichia coli probed with a fluorescent voltage-indicating protein](https://doi.org/10.1126/science.1204763) — Kralj JM, Hochbaum DR, Douglass AD, Cohen AE, Science 2011 (E. coli (BW25113 and other strains), in vitro) - [Initial photophysical characterization of the proteorhodopsin optical proton sensor (PROPS)](https://doi.org/10.3389/fnins.2015.00315) — Nadeau JL, Frontiers in Neuroscience 2015 (E. coli, in vitro) - [Voltage-gated calcium flux mediates Escherichia coli mechanosensation](https://doi.org/10.1073/pnas.1703084114) — Bruni GN, Weekley RA, Dodd BJT, Kralj JM, Proceedings of the National Academy of Sciences 2017 (E. coli, in vitro) - [Membrane voltage dysregulation driven by metabolic dysfunction underlies bactericidal activity of aminoglycosides](https://doi.org/10.7554/eLife.58706) — Bruni GN, Kralj JM, eLife 2020 (E. coli, in vitro) ## QuasAr1 First-generation QuasAr with extremely fast response times. - Category: Opsin GEVI - Published: 2014-06-22 — [Nature Methods 2014](https://doi.org/10.1038/nmeth.3000) - Derived from: [Arch](https://gevibench.org/gevi/arch) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 590 nm, emission peak 715 nm (QuasAr1) - Plasmid: [Addgene #51629](https://www.addgene.org/51629/) - Tags: Archaerhodopsin, Far-red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.0028× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 0.24 / 0.29 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +32% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.25% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 21% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 2.6 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 0.24 ms, τ_off 0.29 ms at 23°C — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) #### ΔF/F per 100 mV - +32%, 1P — [Hochbaum 2014, Fig. 1c](https://doi.org/10.1038/nmeth.3000) #### ΔF/F per action potential - 21%, 1P — [Hochbaum 2014, Fig. 1e](https://doi.org/10.1038/nmeth.3000) #### AP width (FWHM) - 2.6 ms at 2000 Hz sampling, Cultured rat hippocampal neurons, in vitro, 1P, 23°C — [Hochbaum 2014, Fig. 1f](https://doi.org/10.1038/nmeth.3000) #### Brightness comparisons - 15.2× the brightness of Arch — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) - 20× the brightness of Arch — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -11%; -90 mV: -7%; -80 mV: -3%; -70 mV: 0%; -60 mV: 2%; -50 mV: 5%; -40 mV: 8%; -30 mV: 12%; -20 mV: 15%; -10 mV: 18%; 0 mV: 20%; 10 mV: 22%; 20 mV: 25%; 30 mV: 26%; 40 mV: 30%; 50 mV: 31% — [Hochbaum 2014, Fig. 1c](https://doi.org/10.1038/nmeth.3000) ### Research papers using QuasAr1 (1) - [All-optical electrophysiology in mammalian neurons using engineered microbial rhodopsins](https://doi.org/10.1038/nmeth.3000) — Hochbaum DR, Zhao Y, Farhi SL, Klapoetke NC, Werley CA, Kapoor V, Zou P, Kralj JM, Maclaurin D, Smedemark-Margulies N, Saulnier JL, Boulting GL, Straub C, Cho YK, Melkonian M, Wong GKS, Harrison DJ, Murthy VN, Sabatini BL, Boyden ES, Campbell RE, Cohen AE, Nature Methods 2014 (HEK293 cells, cultured rat hippocampal neurons, in vitro) ## QuasAr2 Higher-sensitivity QuasAr variant spike counting and subthreshold event detection. - Category: Opsin GEVI - Published: 2014-06-22 — [Nature Methods 2014](https://doi.org/10.1038/nmeth.3000) - Derived from: [Arch](https://gevibench.org/gevi/arch) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 590 nm, emission peak 715 nm (QuasAr2) - Two-photon compatible: no - Plasmid: [Addgene #51692](https://www.addgene.org/51692/) - Tags: Archaerhodopsin, Far-red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.00086× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.1 / 1.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +90% (median of 3 measurements: +46%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.7% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 48% (median of 2 measurements: 48%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4.5 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 3.1 h | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 23 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 4.6 ms, τ_off 4 ms at 23°C — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) - τ_on 1.4 ms, τ_off 1.3 ms at 34°C — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) - τ_on 0.9 ms, τ_off 1.6 ms at 33-34°C — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - τ_on 4.46 ms, τ_off 6.02 ms at 32°C — [Piatkevich 2018, Table S1](https://doi.org/10.1038/s41589-018-0004-9) #### ΔF/F per 100 mV - +90%, 1P — [Hochbaum 2014, Fig. 1c](https://doi.org/10.1038/nmeth.3000) - +46%, 1P — [Piatkevich 2018, Fig. 1g](https://doi.org/10.1038/s41589-018-0004-9) - +46%, 1P — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) #### ΔF/F per action potential - 48%, 1P — [Hochbaum 2014, Fig. 1g](https://doi.org/10.1038/nmeth.3000) - 48%, 1P — [Zou 2014, Table 1](https://doi.org/10.1038/ncomms5625) #### AP width (FWHM) - 4.5 ms at 1000 Hz sampling, Cultured rat hippocampal neuron (Optopatch2), in vitro, 1P, 34°C — [Hochbaum 2014, Fig. S5C](https://doi.org/10.1038/nmeth.3000) #### Brightness comparisons - 3.4× the brightness of Arch — [Hochbaum 2014, Table S2](https://doi.org/10.1038/nmeth.3000) - 0.36× the brightness of Archon1 — [Piatkevich 2018, Fig. 2b](https://doi.org/10.1038/s41589-018-0004-9) - 1× the brightness of Archer1 — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 0.12484394506866417× the brightness of Archon2 — [Piatkevich 2018, Fig. 2b](https://doi.org/10.1038/s41589-018-0004-9) - 0.0017985611510791368× the brightness of ASAP3 — [Villette 2019, Table 1](https://doi.org/10.1016/j.cell.2019.11.004) - 0.5× the brightness of paQuasAr3 — [Adam 2019, Ext. Fig. 3f](https://doi.org/10.1038/s41586-019-1166-7) #### Photobleaching - t75% = 513 s at 2200 mW/mm², 1P — [Piatkevich 2018, Fig. 2i](https://doi.org/10.1038/s41589-018-0004-9) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -17%; -90 mV: -13%; -80 mV: -6%; -70 mV: 0%; -60 mV: 8%; -50 mV: 16%; -40 mV: 25%; -30 mV: 32%; -20 mV: 41%; -10 mV: 51%; 0 mV: 60%; 10 mV: 69%; 20 mV: 77%; 30 mV: 84%; 40 mV: 91%; 50 mV: 98% — [Hochbaum 2014, Fig. 1c](https://doi.org/10.1038/nmeth.3000) ### Research papers using QuasAr2 (23) - [All-optical electrophysiology in mammalian neurons using engineered microbial rhodopsins](https://doi.org/10.1038/nmeth.3000) — Hochbaum DR, Zhao Y, Farhi SL, Klapoetke NC, Werley CA, Kapoor V, Zou P, Kralj JM, Maclaurin D, Smedemark-Margulies N, Saulnier JL, Boulting GL, Straub C, Cho YK, Melkonian M, Wong GKS, Harrison DJ, Murthy VN, Sabatini BL, Boyden ES, Campbell RE, Cohen AE, Nature Methods 2014 (HEK293 cells, cultured rat hippocampal neurons, mouse brain slices, Drosophila in vivo) - [Two-photon lifetime imaging of voltage indicating proteins as a probe of absolute membrane voltage](https://doi.org/10.1016/j.bpj.2015.07.038) — Brinks D, Klein AJ, Cohen AE, Biophysical Journal 2015 (HEK293T cells and cultured rat hippocampal neurons, in vitro) - [Genetically targeted all-optical electrophysiology with a transgenic Cre-dependent Optopatch mouse](https://doi.org/10.1523/JNEUROSCI.1582-16.2016) — Lou S, Adam Y, Weinstein EN, Williams LA, Williams K, Parot V, Kavokine N, Liberles S, Madisen L, Zeng H, Cohen AE, Journal of Neuroscience 2016 (Mouse, DRG neurons and brain slices, in vitro/in vivo) - [Optical electrophysiology for probing function and pharmacology of voltage-gated ion channels](https://doi.org/10.7554/eLife.15202) — Zhang H, Reichert E, Cohen AE, eLife 2016 (HEK293 cells stably expressing NaV channels, in vitro) - [Cardiotoxicity screening with simultaneous optogenetic pacing, voltage imaging and calcium imaging](https://doi.org/10.1016/j.vascn.2016.05.003) — Dempsey GT, Chaudhary KW, Atwater N, Nguyen C, Brown BS, McNeish JD, Cohen AE, Kralj JM, Journal of Pharmacological and Toxicological Methods 2016 (Human iPSC-derived cardiomyocytes, in vitro) - [All-optical electrophysiology for disease modeling and pharmacological characterization of neurons](https://doi.org/10.1002/cpph.25) — Werley CA, Brookings T, Upadhyay H, Williams LA, McManus OB, Dempsey GT, Current Protocols in Pharmacology 2017 (Rat hippocampal neurons and human iPSC-derived neurons, in vitro) - [Ultrawidefield microscope for high-speed fluorescence imaging and targeted optogenetic stimulation](https://doi.org/10.1364/BOE.8.005794) — Werley CA, Chien MP, Cohen AE, Biomedical Optics Express 2017 (Cultured neurons expressing Optopatch2, in vitro) - [Geometry-dependent functional changes in iPSC-derived cardiomyocytes probed by functional imaging and RNA sequencing](https://doi.org/10.1371/journal.pone.0172671) — Werley CA, Chien MP, Gaublomme J, Shekhar K, Butty V, Yi BA, Kralj JM, Bhatt R, Boyer LA, Regev A, Cohen AE, PLOS ONE 2017 (Human iPSC-derived cardiomyocytes, in vitro) - [Evaluation of optogenetic electrophysiology tools in human stem cell-derived cardiomyocytes](https://doi.org/10.3389/fphys.2017.00884) — Bjork S, Ojala EA, Nordstrom T, Ahola A, Liljestrom M, Hyttinen J, Kankuri E, Mervaala E, Frontiers in Physiology 2017 (Human iPSC-derived cardiomyocytes, in vitro) - [A dimeric fluorescent protein yields a bright, red-shifted GEVI capable of population signals in brain slice](https://doi.org/10.1038/s41598-018-33297-y) — Yi B, Bhatt D, Bhatt R, Baker BJ, Scientific Reports 2018 (Mouse hippocampal brain slices, ex vivo) - [All-optical electrophysiology for high-throughput functional characterization of a human iPSC-derived motor neuron model of ALS](https://doi.org/10.1016/j.stemcr.2018.04.020) — Kiskinis E, Kralj JM, Zou P, Weinstein EN, Zhang H, Tsioras K, Wiskow O, Ortega JA, Eggan K, Cohen AE, Stem Cell Reports 2018 (Human iPSC-derived motor neurons (ALS model), in vitro) - [Optical interrogation of neuronal circuitry in zebrafish using genetically encoded voltage indicators](https://doi.org/10.1038/s41598-018-23906-1) — Miyazawa H, Okumura K, Hiyoshi K, Maruyama K, Kakinuma H, Amo R, Okamoto H, Yamasu K, Tsuda S, Scientific Reports 2018 (Zebrafish, larval brain, in vivo) - [Comparative evaluation of genetically encoded voltage indicators](https://doi.org/10.1016/j.celrep.2018.12.088) — Bando Y, Sakamoto M, Kim S, Ayzenshtat I, Yuste R, Cell Reports 2019 (Mouse, cultured hippocampal neurons and visual cortex in vivo) - [Electrophysiological characterization of drug response in hSC-derived cardiomyocytes using voltage-sensitive optical platforms](https://doi.org/10.1016/j.vascn.2019.106612) — Pfeiffer-Kaushik ER, Smith GL, Cai B, Dempsey GT, Bhatt D, Bhatt R, Hortigon-Vinagre MP, Zamora V, Smith G, Journal of Pharmacological and Toxicological Methods 2019 (Human stem cell-derived cardiomyocytes, in vitro) - [Simultaneous voltage and calcium imaging and optogenetic stimulation with high sensitivity and a wide field of view](https://doi.org/10.1364/BOE.10.000789) — Nguyen C, Bhatt D, Bhatt R, Rozsahegyi EJ, Bhatt R, Werley CA, Biomedical Optics Express 2019 (Human iPSC-derived cardiomyocytes, in vitro) - [Rhodopsin-based voltage imaging tools for use in muscles and neurons of Caenorhabditis elegans](https://doi.org/10.1073/pnas.1902443116) — Azimi Hashemi N, Bergs ACF, Schuler C, Scheiwe AR, Steuer Costa W, Bach M, Liewald JF, Gottschalk A, Proceedings of the National Academy of Sciences 2019 (C. elegans, body wall muscles and neurons, in vivo) - [Highly parallelized, multicolor optogenetic recordings of cellular activity for therapeutic discovery applications in ion channels and disease-associated excitable cells](https://doi.org/10.3389/fnmol.2022.896320) — Borja G, Zhang H, Harwood J, Jacques K, Bhatt D, Bhatt R, Bhatt R, Werley CA, Frontiers in Molecular Neuroscience 2022 (HEK293 cells expressing NaV channels, in vitro) - [Human cancer cells generate spontaneous calcium transients and intercellular waves that modulate tumor growth](https://doi.org/10.1016/j.biomaterials.2022.121823) — Liang H, Zhang C, Chen H, Liu T, Tanaka T, Wang Y, Biomaterials 2022 (Human colon and prostate cancer cells, in vitro/in vivo) - [All-optical closed-loop voltage clamp for precise control of muscles and neurons in live animals](https://doi.org/10.1038/s41467-023-37622-6) — Bergs ACF, Liewald JF, Rodriguez-Rozada S, Liu Q, Wirt C, Bessel A, Zeitzschel N, Durmaz H, Nozownik A, Dill H, Jospin M, Vierock J, Bargmann CI, Hegemann P, Wiegert JS, Gottschalk A, Nature Communications 2023 (C. elegans, muscles and neurons; rat hippocampal neurons, in vitro/in vivo) - [A phenotypic screening platform for chronic pain therapeutics using all-optical electrophysiology](https://doi.org/10.1097/j.pain.0000000000003090) — Liu S, Zhang H, Werley CA, Bhatt D, Bhatt R, Bhatt R, Bhatt D, Bhatt R, PAIN 2024 (Mouse DRG sensory neurons, in vitro) - [A robotic multidimensional directed evolution approach applied to fluorescent voltage reporters](https://doi.org/10.1038/s41589-018-0004-9) — Piatkevich KD, Jung EE, Straub C, Linghu C, Park D, Suk HJ, Hochbaum DR, Goodwin D, Pnevmatikakis E, Pak N, Kawashima T, Yang CT, Rhoades JL, Shemesh O, Asano S, Yoon YG, Freifeld L, Saulnier JL, Riegler C, Engert F, Hughes T, Drobizhev M, Szabo B, Ahrens MB, Flavell SW, Sabatini BL, Boyden ES, Nature Chemical Biology 2018 (HEK293T cells and cultured mouse hippocampal neurons, in vitro) - [Ultrafast two-photon imaging of a high-gain voltage indicator in awake behaving mice](https://doi.org/10.1016/j.cell.2019.11.004) — Villette V, Chavarha M, Dimov IK, Bradley J, Pradhan L, Mathieu B, Evans SW, Chamberland S, Shi D, Yang R, Kim BB, Ayon A, Jalil A, St-Pierre F, Schnitzer MJ, Bi G, Toth K, Ding J, Dieudonne S, Lin MZ, Cell 2019 (HEK293 cells, cultured neurons, and mouse brain in vivo) - [Screening and cellular characterization of genetically encoded voltage indicators based on near-infrared fluorescent proteins](https://doi.org/10.1021/acschemneuro.0c00046) — Monakhov MV, Matlashov ME, Colavita M, Song C, Shcherbakova DM, Antic SD, Verkhusha VV, Knopfel T, ACS Chemical Neuroscience 2020 (HEK293T cells and cultured mouse hippocampal neurons, in vitro) ## QuasAr6a Archon1 variant evolved through video-based pooled screening with improved SNR. - Category: Opsin GEVI - Published: 2023-01-09 — [Nature Methods 2023](https://doi.org/10.1038/s41592-022-01743-5) - Derived from: [Archon1](https://gevibench.org/gevi/archon1) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 590 nm, emission peak 715 nm (QuasAr6a) - Plasmid: [Addgene #178822](https://www.addgene.org/178822/) - Tags: Archaerhodopsin, Far-red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.0066× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.3 / 1.6 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +73% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.7% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 23% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 2.4 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 5.2 h | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 5 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.3 ms, τ_off 1.6 ms at 30°C — [Tian 2023, Ext. Fig. 4e](https://doi.org/10.1038/s41592-022-01743-5) #### ΔF/F per 100 mV - +73%, 1P — [Tian 2023, Ext. Fig. 4c](https://doi.org/10.1038/s41592-022-01743-5) #### ΔF/F per action potential - 23%, 1P — [Tian 2023, Fig. 3i](https://doi.org/10.1038/s41592-022-01743-5) #### AP width (FWHM) - 2.4 ms at 1000 Hz sampling, Mouse, visual cortex layer 1 NDNF interneurons, in vivo, 1P, 37°C — [Tian 2023, Fig. 4d](https://doi.org/10.1038/s41592-022-01743-5) #### Brightness comparisons - 1.7× the brightness of Archon1 — [Tian 2023, Ext. Fig. 4b](https://doi.org/10.1038/s41592-022-01743-5) #### Photobleaching - t75% = 445 s at 4200 mW/mm², 1P — [Tian 2023, Ext. Fig. 4f](https://doi.org/10.1038/s41592-022-01743-5) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -70 mV: 0%; -60 mV: 7%; -50 mV: 15%; -40 mV: 22%; -30 mV: 29%; -20 mV: 37%; -10 mV: 44%; 0 mV: 51%; 10 mV: 58%; 20 mV: 66%; 30 mV: 73% — [Tian 2023, Ext. Fig. 4c](https://doi.org/10.1038/s41592-022-01743-5) ### Research papers using QuasAr6a (5) - [Video-based pooled screening yields improved far-red genetically encoded voltage indicators](https://doi.org/10.1038/s41592-022-01743-5) — Tian H, Davis HC, Wong-Campos JD, Park P, Fan LZ, Gmeiner B, Begum S, Werley CA, Borja GB, Upadhyay H, Shah H, Jacques J, Qi Y, Parot V, Deisseroth K, Cohen AE, Nature Methods 2023 (HEK293T cells, in vitro; Cultured rat hippocampal neurons, in vitro; Mouse cortex NDNF interneurons, in vivo; Mouse hippocampus PV interneurons, in vivo) - [Dendritic branch structure compartmentalizes voltage-dependent calcium influx in cortical layer 2/3 pyramidal cells](https://doi.org/10.7554/eLife.76993) — Landau AT, Park P, Wong-Campos JD, Tian H, Cohen AE, Sabatini BL, eLife 2022 (Mouse, cortical layer 2/3 pyramidal cells, acute brain slices) - [Diminishing neuronal acidification by channelrhodopsins with low proton conduction](https://doi.org/10.7554/eLife.86833) — Hayward RF, Brooks FP 3rd, Yang S, Gao S, Cohen AE, eLife 2023 (Rat, cultured hippocampal neurons, in vitro; HEK293T cells, in vitro) - [Retrograde endocannabinoid signaling at inhibitory synapses in vivo](https://doi.org/10.1126/science.adk3863) — Dudok B, Fan LZ, Farrell JS, Malhotra S, Homidan J, Kim DK, Wenardy C, Ramakrishnan C, Li Y, Deisseroth K, Soltesz I, Science 2024 (Mouse, hippocampus CA1, in vivo) - [Plasmonic Enhancement of Fluorescence and Protein Dynamics in Living Mammalian Cells](https://doi.org/10.1002/adma.202501944) — Locarno M, Dong Q, Post M, Meng X, Glessi C, Hettema NM, Brandsma N, Blokhuizen S, Castaneda Garcia A, Ganapathy S, Schmidt T, van Roemburg L, Xu B, Cho CT, Laan L, Chien M, Brinks D, Advanced Materials 2026 (HEK293T cells, in vitro) ## QuasAr6b Archon1 variant evolved through video-based pooled screening with improved speed. - Category: Opsin GEVI - Published: 2023-01-09 — [Nature Methods 2023](https://doi.org/10.1038/s41592-022-01743-5) - Derived from: [Archon1](https://gevibench.org/gevi/archon1) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 590 nm, emission peak 715 nm (QuasAr6b) - Plasmid: [Addgene #178823](https://www.addgene.org/178823/) - Tags: Archaerhodopsin, Far-red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.0078× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.6 / 1.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +24% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.2% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 14% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 1.6 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 4.7 h | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.6 ms, τ_off 1.5 ms at 30°C — [Tian 2023, Ext. Fig. 4e](https://doi.org/10.1038/s41592-022-01743-5) #### ΔF/F per 100 mV - +24%, 1P — [Tian 2023, Ext. Fig. 4c](https://doi.org/10.1038/s41592-022-01743-5) #### ΔF/F per action potential - 14%, 1P — [Tian 2023, Fig. 3i](https://doi.org/10.1038/s41592-022-01743-5) #### AP width (FWHM) - 0.87 ms at 2000 Hz sampling, Mouse, hippocampal PV interneurons, in vivo, 1P — [Tian 2023, Ext. Fig. 8f](https://doi.org/10.1038/s41592-022-01743-5) - 2.3 ms at 1000 Hz sampling, Mouse, visual cortex layer 1 NDNF interneurons, in vivo, 1P — [Tian 2023, Fig. 4d](https://doi.org/10.1038/s41592-022-01743-5) #### Brightness comparisons - 2× the brightness of Archon1 — [Tian 2023, Ext. Fig. 4b](https://doi.org/10.1038/s41592-022-01743-5) #### Photobleaching - t75% = 405 s at 4200 mW/mm², 1P — [Tian 2023, Ext. Fig. 4f](https://doi.org/10.1038/s41592-022-01743-5) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -70 mV: 0%; -60 mV: 2%; -50 mV: 5%; -40 mV: 7%; -30 mV: 10%; -20 mV: 12%; -10 mV: 14%; 0 mV: 17%; 10 mV: 19%; 20 mV: 22%; 30 mV: 24% — [Tian 2023, Ext. Fig. 4c](https://doi.org/10.1038/s41592-022-01743-5) ### Research papers using QuasAr6b (2) - [Video-based pooled screening yields improved far-red genetically encoded voltage indicators](https://doi.org/10.1038/s41592-022-01743-5) — Tian H, Davis HC, Wong-Campos JD, Park P, Fan LZ, Gmeiner B, Begum S, Werley CA, Borja GB, Upadhyay H, Shah H, Jacques J, Qi Y, Parot V, Deisseroth K, Cohen AE, Nature Methods 2023 (HEK293T cells, in vitro; Cultured rat hippocampal neurons, in vitro; Mouse cortex NDNF interneurons, in vivo; Mouse hippocampus PV interneurons, in vivo) - [All-optical electrophysiology reveals behavior-dependent dynamics of excitation and inhibition in the hippocampus](https://doi.org/10.1016/j.neuron.2025.12.040) — Yang Q, Baror-Sebban S, Kipper R, London M, Adam Y, Neuron 2026 (Mouse, hippocampus CA1 PV interneurons, in vivo) ## rEstus Variant of ASAP3 optimized for non-excitable cells, shifting voltage sensitivity to match their characteristically negative resting potentials. - Category: VSD-cpGFP GEVI - Published: 2024-03-25 — [Advanced Science 2024](https://doi.org/10.1002/advs.202307938) - Derived from: [ASAP3](https://gevibench.org/gevi/asap3) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 463 nm, emission peak 513 nm (rEstus) - Plasmid: [Addgene #209767](https://www.addgene.org/209767/) - Tags: cpGFP ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.85× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 14 / 51 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -62% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.3% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 5 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 13.5 ms, τ_off 51 ms at 23°C — [Rühl 2024, Fig. S9](https://doi.org/10.1002/advs.202307938) #### ΔF/F per 100 mV - -62%, 1P — [Rühl 2024, Fig. 1G](https://doi.org/10.1002/advs.202307938) #### ΔF/F per mV (subthreshold) - 1.25%/mV (Peak fractional voltage sensitivity (dF/F dV-1, %/mV) read from Fig. S2 of the rEstus2s paper, the first derivative of the Boltzmann F-V fit divided by the fit; rEstus (black) peaks at ~1.25 %/mV near -10 to 0 mV. Re-sourced here because the origin paper's Fig. 1H plots absolute |dB/dVm| in %EGFP/mV (a different quantity), not fractional %/mV. On the same axis the sibling rEstus2s (red) peaks at ~2.0 %/mV near +5 mV (about 1.6-fold over rEstus across the -100 to 0 mV resting range).) — [Rühl 2026, Fig. S2](https://doi.org/10.64898/2026.02.10.701308) #### Brightness comparisons - 0.775× the brightness of EGFP — [Rühl 2024, Fig. 1G](https://doi.org/10.1002/advs.202307938) - 2.07× the brightness of ASAP3 — [Rühl 2024, Table 1](https://doi.org/10.1002/advs.202307938) - 1.71× the brightness of ASAP3 — [Nair 2025, Table S1](https://doi.org/10.1021/acschemneuro.5c00670) - 0.9569377990430623× the brightness of rEstus-NI — [Nair 2025, Fig. 2C](https://doi.org/10.1021/acschemneuro.5c00670) - 1.669449081803005× the brightness of rEstus2s — [Rühl 2026, Table S1](https://doi.org/10.64898/2026.02.10.701308) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 13%; -100 mV: 10%; -80 mV: 5%; -70 mV: 0%; -60 mV: -6%; -40 mV: -20%; -20 mV: -36%; 0 mV: -50%; 20 mV: -59%; 40 mV: -64%; 60 mV: -67%; 75 mV: -68% — [Rühl 2024, Fig. 1G](https://doi.org/10.1002/advs.202307938) ### Research papers using rEstus (5) - [An Ultrasensitive Genetically Encoded Voltage Indicator Uncovers the Electrical Activity of Non-Excitable Cells](https://doi.org/10.1002/advs.202307938) — Rühl P, et al., Advanced Science 2024 (HEK293T cells; A375 melanoma cells; MCF-7 breast cancer cells, in vitro) - [Sub-Millivolt Voltage Imaging Reveals Gap Junction-Mediated Bioelectric Contact Inhibition](https://doi.org/10.64898/2026.02.10.701308) — Rühl P, et al., bioRxiv 2026 (HEK293T cells, in vitro (rEstus characterized under whole-cell voltage clamp alongside rEstus2s)) - [Absolute Membrane Potential Recording with ASAP-Type Genetically Encoded Voltage Indicators Using Fluorescence Lifetime Imaging](https://doi.org/10.1021/acschemneuro.5c00670) — Nair AG, et al., ACS Chemical Neuroscience 2025 (HEK293T cells; A375 melanoma cells; MCF-7 breast cancer cells, in vitro) - [Crosstalk of KCNH1 and KCNH5 gain-of-function mutations leading to epilepsy and neurodevelopmental disorders](https://doi.org/10.1186/s13041-026-01279-1) — Bernert A, et al., Molecular Brain 2026 (HEK293T cells, in vitro) - [Generation and characterization of a human induced pluripotent stem cell line (hiPSC) expressing the rEstus voltage sensor under doxycycline induction](https://doi.org/10.1016/j.scr.2026.103972) — Malan D, et al., Stem Cell Research 2026 (Human iPSC, in vitro) ## rEstus-NI Variant of rEstus optimized for fluorescence lifetime imaging and absolute membrane potential measurement. - Category: VSD-cpGFP GEVI - Published: 2025-12-17 — [ACS Chemical Neuroscience 2025](https://doi.org/10.1021/acschemneuro.5c00670) - Derived from: [rEstus](https://gevibench.org/gevi/restus) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 463 nm, emission peak 513 nm (rEstus-NI) - Tags: cpGFP ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.84× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 181 / 433 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -57% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.1% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 181 ms, τ_off 433 ms at 20-23°C — [Nair 2025, Fig. S6C](https://doi.org/10.1021/acschemneuro.5c00670) #### ΔF/F per 100 mV - -57%, 1P — [Nair 2025, Fig. 1F](https://doi.org/10.1021/acschemneuro.5c00670) #### Brightness comparisons - 1.045× the brightness of rEstus — [Nair 2025, Fig. 2C](https://doi.org/10.1021/acschemneuro.5c00670) - 1.788× the brightness of ASAP3 — [Nair 2025, Fig. 2C](https://doi.org/10.1021/acschemneuro.5c00670) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 66%; -100 mV: 40%; -80 mV: 11%; -70 mV: 0%; -60 mV: -11%; -40 mV: -30%; -20 mV: -42%; 0 mV: -51%; 20 mV: -55%; 40 mV: -58%; 60 mV: -61% — [Nair 2025, Fig. 1F](https://doi.org/10.1021/acschemneuro.5c00670) ### Research papers using rEstus-NI (1) - [Absolute Membrane Potential Recording with ASAP-Type Genetically Encoded Voltage Indicators Using Fluorescence Lifetime Imaging](https://doi.org/10.1021/acschemneuro.5c00670) — Nair AG, Rodewald M, Bae H, Rühl P, Popp J, Schmitt M, Meyer-Zedler T, Heinemann SH, ACS Chemical Neuroscience 2025 (HEK293T cells; A375 melanoma cells; MCF-7 breast cancer cells, in vitro) ## rEstus2s Rationally engineered variant of rEstus with enhanced voltage sensitivity tuned for sub-millivolt resolution across the physiological resting potential range of non-excitable cells. - Category: VSD-cpGFP GEVI - Published: 2026-02-11 — [bioRxiv 2026](https://doi.org/10.64898/2026.02.10.701308) - Derived from: [rEstus](https://gevibench.org/gevi/restus) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 460 nm, emission peak 505 nm (rEstus2s) - Plasmid: [Addgene #250991](https://www.addgene.org/250991/) - Tags: cpGFP, Green ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.56× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 12 / 42 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -83% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1.6% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 11.9 ms, τ_off 42 ms at 23°C — [Rühl 2026, Fig. S3](https://doi.org/10.64898/2026.02.10.701308) #### ΔF/F per 100 mV - -83%, 1P — [Rühl 2026, Fig. 1g](https://doi.org/10.64898/2026.02.10.701308) #### ΔF/F per mV (subthreshold) - 1.65%/mV (Fractional voltage sensitivity (dF/F dV-1) at -50 mV, the average resting Vm of HEK293T cells, read from Fig. S2 (peak ~1.65 %/mV near -50 mV). Highest sensitivity of all tested GEVIs across the physiological resting Vm range.) — [Rühl 2026, Fig. S2](https://doi.org/10.64898/2026.02.10.701308) #### Brightness comparisons - 0.599× the brightness of rEstus — [Rühl 2026, Table S1](https://doi.org/10.64898/2026.02.10.701308) - 1.078× the brightness of ASAP3 — [Rühl 2026, Table S1](https://doi.org/10.64898/2026.02.10.701308) - 0.738× the brightness of JEDI-1P — [Rühl 2026, Table S1](https://doi.org/10.64898/2026.02.10.701308) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 45%; -100 mV: 33%; -80 mV: 12%; -70 mV: 0%; -60 mV: -13%; -40 mV: -38%; -20 mV: -58%; 0 mV: -71%; 20 mV: -80%; 40 mV: -86%; 60 mV: -88%; 80 mV: -90% — [Rühl 2026, Fig. 1g](https://doi.org/10.64898/2026.02.10.701308) ### Research papers using rEstus2s (1) - [Sub-Millivolt Voltage Imaging Reveals Gap Junction-Mediated Bioelectric Contact Inhibition](https://doi.org/10.64898/2026.02.10.701308) — Rühl P, Hussein R, Reuter S, Frahnert K, Nair AG, Mrowka R, Schönherr R, Heinemann SH, bioRxiv 2026 (HEK293T cells, in vitro) ## Solaris Novel chemigenetic voltage indicator that inserts a dye-binding tag into the rhodopsin itself, achieving substantially higher voltage sensitivity than previous Voltron-family sensors. - Category: Chemigenetic GEVI - Published: 2024-02-04 — [bioRxiv 2024](https://doi.org/10.1101/2024.02.02.578569) - Derived from: [Voltron2](https://gevibench.org/gevi/voltron2); also related to [Cepheid1b](https://gevibench.org/gevi/cepheid1b) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 593 nm, emission peak 611 nm (Solaris (JF585)) - Tags: Ace opsin, cpHaloTag, Red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.5 / 2.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -53% (median of 5 measurements: −53%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 1% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | -28.1% (median of 5 measurements: −28.1%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 12 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 2.53 ms, τ_off 2.53 ms at 25°C — [Yang 2024, Main text](https://doi.org/10.1101/2024.02.02.578569) #### ΔF/F per 100 mV - -53%, 1P, dye JF585 — [Yang 2024, Fig. 1C](https://doi.org/10.1101/2024.02.02.578569) - -52%, 1P, dye JF552 — [Yang 2024, Fig. 1C](https://doi.org/10.1101/2024.02.02.578569) - -52%, 1P, dye JF549 — [Yang 2024, Fig. 1C](https://doi.org/10.1101/2024.02.02.578569) - -51%, 1P, dye JF525 — [Yang 2024, Fig. 1C](https://doi.org/10.1101/2024.02.02.578569) - -23%, 1P, dye JF635 — [Yang 2024, Fig. 1C](https://doi.org/10.1101/2024.02.02.578569) #### ΔF/F per action potential - -28.1%, 1P, dye JF585 — [Yang 2024, Fig. 2B](https://doi.org/10.1101/2024.02.02.578569) - -26.5%, 1P, dye JF552 — [Yang 2024, Fig. 2B](https://doi.org/10.1101/2024.02.02.578569) - -22.6%, 1P, dye JF549 — [Yang 2024, Fig. 2B](https://doi.org/10.1101/2024.02.02.578569) - -21.9%, 1P, dye JF525 — [Yang 2024, Fig. 2B](https://doi.org/10.1101/2024.02.02.578569) - -7.9%, 1P, dye JF635 — [Yang 2024, Fig. 2B](https://doi.org/10.1101/2024.02.02.578569) #### AP width (FWHM) - 11.5 ms at 484 Hz sampling, Rat, hippocampal neurons, in vitro, 1P — [Yang 2024, Fig. 2B](https://doi.org/10.1101/2024.02.02.578569) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 33%; -80 mV: 7%; -70 mV: 0%; -60 mV: -13%; -40 mV: -27%; -20 mV: -38%; 0 mV: -45%; 20 mV: -51%; 40 mV: -55% — [Yang 2024, Fig. 1C](https://doi.org/10.1101/2024.02.02.578569) ### Research papers using Solaris (1) - [Solaris: a panel of bright and sensitive hybrid voltage indicators for imaging membrane potential in cultured neurons](https://doi.org/10.1101/2024.02.02.578569) — Yang J, et al., bioRxiv 2024 (HEK293T cells; rat hippocampal neurons, in vitro) ## SomArchon Soma-targeted Archon1 variant designed for population voltage imaging. - Category: Opsin GEVI - Published: 2019-10-17 — [Nature 2019](https://doi.org/10.1038/s41586-019-1641-1) - Derived from: [Archon1](https://gevibench.org/gevi/archon1) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 586 nm, emission peak 693 nm (SomArchon) - Plasmid: [Addgene #126941](https://www.addgene.org/126941/) - Tags: Archaerhodopsin, Red ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.01× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 0.60 / 1.1 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +30% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.35% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 43% (median of 4 measurements: 40%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4.7 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 49.0 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 16 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 0.6 ms, τ_off 1.1 ms at 37°C — [Lowet 2022, Main text](https://doi.org/10.1038/s41467-022-35314-1) #### ΔF/F per 100 mV - +30%, 1P — [Piatkevich 2019, Fig. 1g](https://doi.org/10.1038/s41586-019-1641-1) #### ΔF/F per action potential - 43%, 1P — [Piatkevich 2019, Fig. 1d](https://doi.org/10.1038/s41586-019-1641-1) - 37%, 1P — [Piatkevich 2019, Fig. 1d](https://doi.org/10.1038/s41586-019-1641-1) - 29%, 1P — [Piatkevich 2019, Fig. 1d](https://doi.org/10.1038/s41586-019-1641-1) - 53.4%, 1P — [Piatkevich 2019, Ext. Fig. 5c](https://doi.org/10.1038/s41586-019-1641-1) #### AP width (FWHM) - 5.3 ms at 1000 Hz sampling, Mouse, cortex layer 2/3, acute brain slice; optical AP evoked by current injection, whole-cell patch clamp, 1P, 22°C — [Piatkevich 2019, Fig. 1e](https://doi.org/10.1038/s41586-019-1641-1) - 4.7 ms at 1000 Hz sampling, Mouse, hippocampus, acute brain slice; optical AP evoked by current injection, whole-cell patch clamp, 1P, 22°C — [Piatkevich 2019, Fig. 1e](https://doi.org/10.1038/s41586-019-1641-1) - 4.4 ms at 1000 Hz sampling, Mouse, striatum, acute brain slice; optical AP evoked by current injection, whole-cell patch clamp, 1P, 22°C — [Piatkevich 2019, Fig. 1e](https://doi.org/10.1038/s41586-019-1641-1) #### Brightness comparisons - 28× the brightness of Arch — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 0.31545741324921134× the brightness of nirButterfly — [Monakhov 2020, Fig. S2](https://doi.org/10.1021/acschemneuro.0c00046) #### Photobleaching - curve only (did not reach 75% within the measured window) at 44 mW/mm², 1P — [Monakhov 2020, Fig. S2](https://doi.org/10.1021/acschemneuro.0c00046) - t75% = 196 s at 1500 mW/mm² (637 nm), 1P — [Piatkevich 2019, Ext. Fig. 5e](https://doi.org/10.1038/s41586-019-1641-1) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -9%; -80 mV: -3%; -70 mV: 0%; -60 mV: 4%; -40 mV: 11%; -20 mV: 17%; 0 mV: 22%; 20 mV: 26%; 40 mV: 30%; 60 mV: 32% — [Piatkevich 2019, Fig. 1g](https://doi.org/10.1038/s41586-019-1641-1) ### Research papers using SomArchon (16) - [Population imaging of neural activity in awake behaving mice](https://doi.org/10.1038/s41586-019-1641-1) — Piatkevich KD, Bensussen S, Tseng HA, Shroff SN, Lopez-Huerta VG, Park D, Jung EE, Shemesh OA, Straub C, Gritton HJ, Romano MF, Costa E, Sabatini BL, Fu Z, Boyden ES, Han X, Nature 2019 (Mouse, cortex, hippocampus CA1, and striatum, in vivo awake head-fixed) - [All-optical electrophysiology reveals the role of lateral inhibition in sensory processing in cortical layer 1](https://doi.org/10.1016/j.cell.2020.01.001) — Fan LZ, Kheifets S, Bohm UL, Wu H, Piatkevich KD, Xie ME, Parot V, Ha Y, Evans KE, Boyden ES, Takesian AE, Cohen AE, Cell 2020 (Mouse, barrel cortex layer 1 interneurons, in vivo awake) - [Craniotomy Procedure for Visualizing Neuronal Activities in Hippocampus of Behaving Mice](https://doi.org/10.3791/62266) — Wang Y, Zhu D, Liu B, Piatkevich KD, Journal of Visualized Experiments 2021 (Mouse, hippocampus CA1, in vivo awake head-fixed) - [Large-scale voltage imaging in behaving mice using targeted illumination](https://doi.org/10.1016/j.isci.2021.103263) — Xiao S, Lowet E, Gritton HJ, Fabris P, Wang Y, Sherman J, Mount R, Tseng HA, Man HY, Mertz J, Han X, iScience 2021 (Mouse, visual cortex and hippocampal CA1, in vivo awake; rat cortical neurons, in vitro) - [Region-specific effects of ultrasound on individual neurons in the awake mammalian brain](https://doi.org/10.1016/j.isci.2021.102955) — Tseng HA, Mahoney CE, Bhatt DK, Xiao S, Bhatt RA, De La Croix Bhatt RS, Han X, iScience 2021 (Mouse, hippocampus and motor cortex, in vivo awake) - [Visualizing Oscillations in Brain Slices With Genetically Encoded Voltage Indicators](https://doi.org/10.3389/fnana.2021.741711) — Rhee JK, Iwamoto Y, Baker BJ, Frontiers in Neuroanatomy 2021 (Mouse, motor cortex brain slices, in vitro) - [Deep brain stimulation creates informational lesion through membrane depolarization in mouse hippocampus](https://doi.org/10.1038/s41467-022-35314-1) — Lowet E, Kondabolu K, Zhou S, Mount RA, Ravasio C, Han X, Nature Communications 2022 (Mouse, hippocampal CA1, in vivo awake) - [Membrane Voltage Dynamics of Parvalbumin Interneurons Orchestrate Hippocampal Theta Rhythmicity](https://doi.org/10.1101/2022.11.14.516448) — Tseng HA, Bhatt DK, Bhatt RS, Han X, bioRxiv 2022 (Mouse, hippocampal CA1 parvalbumin interneurons and pyramidal cells, in vivo awake) - [Theta and gamma rhythmic coding through two spike output modes in the hippocampus during spatial navigation](https://doi.org/10.1016/j.celrep.2023.112906) — Lowet E, Sheehan DJ, Chialva U, De Oliveira Pena R, Mount RA, Xiao S, Zhou SL, Tseng HA, Gritton H, Shroff S, Kondabolu K, Cheung C, Wang Y, Piatkevich KD, Boyden ES, Mertz J, Hasselmo ME, Rotstein HG, Han X, Cell Reports 2023 (Mouse, hippocampal CA1, in vivo awake head-fixed) - [Striatal cholinergic interneuron membrane voltage tracks locomotor rhythms in mice](https://doi.org/10.1038/s41467-023-39497-z) — Shroff SN, Lowet E, Sridhar S, Gritton HJ, Abumuaileq M, Tseng HA, Cheung C, Zhou SL, Kondabolu K, Han X, Nature Communications 2023 (Mouse, striatum cholinergic interneurons and spiny projection neurons, in vivo awake) - [Photothrombosis induced cortical stroke produces electrographic epileptic biomarkers in mice](https://doi.org/10.1101/2024.03.01.582958) — Shaw DC, Kondabolu K, Bhatt DK, Han X, bioRxiv 2024 (Mouse, motor cortex, in vivo awake) - [Slow and fast cortical cholinergic arousal is reduced in a mouse model of focal seizures with impaired consciousness](https://doi.org/10.1016/j.celrep.2024.115012) — Sieu LA, Bhatt DK, Bhatt RS, Han X, Cell Reports 2024 (Mouse, cortex, in vivo awake) - [Large-scale deep tissue voltage imaging with targeted-illumination confocal microscopy](https://doi.org/10.1038/s41592-024-02275-w) — Xiao S, Cunningham WJ, Kondabolu K, Lowet E, Moya MV, Mount R, Ravasio C, Bortz E, Shaw D, Economo MN, Han X, Mertz J, Nature Methods 2024 (Mouse, visual cortex, motor cortex, and hippocampal CA1, in vivo awake) - [Relative phase of membrane potential theta oscillations between individual hippocampal neurons code space](https://doi.org/10.1101/2025.11.14.688496) — Athif M, et al., bioRxiv 2025 (Mouse, hippocampal CA1, in vivo awake head-fixed) - [Imaging high-frequency voltage dynamics in multiple neuron classes of behaving mammals](https://doi.org/10.1016/j.cell.2025.06.028) — Haziza S, et al., Cell 2025 (Mouse and rat, cortex, hippocampus, striatum, in vivo awake; fiber photometry with TEMPO) - [Transcranial ultrasound stimulation modulates neuronal membrane potentials across broad timescales in the awake mammalian brain](https://doi.org/10.1016/j.brs.2025.09.004) — Bortz E, et al., Brain Stimulation 2025 (Mouse, cortex, in vivo awake) ## VADER1 Red-emitting voltage indicator built on the JEDI/ASAP architecture with a circularly permuted mApple for reliable spike detection under in vivo 2P. - Category: VSD-single FP - Published: 2026-06-03 — [bioRxiv 2026](https://doi.org/10.64898/2026.06.01.726307) - Derived from: [JEDI-2P](https://gevibench.org/gevi/jedi2p) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 567 nm, emission peak 592 nm (VADER1) - Two-photon compatible: yes - Tags: cpmApple, Red, Two-photon, Positive-going ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.42× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.4 / 5.2 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +42% (median of 2 measurements: +42%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.067% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 40% (median of 2 measurements: 54.5%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 3.6 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.41 ms, τ_off 5.21 ms at 33°C — [Yang 2026, Table 1](https://doi.org/10.64898/2026.06.01.726307) #### ΔF/F per 100 mV - +42%, 1P — [Yang 2026, Fig. 1H](https://doi.org/10.64898/2026.06.01.726307) - +130%, 2P — [Yang 2026, Fig. 2D](https://doi.org/10.64898/2026.06.01.726307) #### ΔF/F per action potential - 40%, 2P — [Yang 2026, Fig. 2G](https://doi.org/10.64898/2026.06.01.726307) - 68.9%, 2P — [Yang 2026, Fig. 3B](https://doi.org/10.64898/2026.06.01.726307) #### AP width (FWHM) - 1.2 ms at 7142.9 Hz sampling, Mouse, visual cortex L2/3, awake head-fixed, in vivo, 2P, 37°C — [Yang 2026, Fig. 3C](https://doi.org/10.64898/2026.06.01.726307) - 6 ms at 440 Hz sampling, HEK293a cells, whole-cell voltage clamp, in vitro, 2P, 22°C — [Yang 2026, Fig. S2.2A](https://doi.org/10.64898/2026.06.01.726307) #### Brightness comparisons - 0.85× the brightness of FlicR2 — [Yang 2026, Fig. 2C](https://doi.org/10.64898/2026.06.01.726307) #### Photobleaching - t75% = 104 s at 22.5 mW at 1045 nm (ULoVE 2P, brain surface), 2P — [Yang 2026, Fig. 3F](https://doi.org/10.64898/2026.06.01.726307) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -1%; -70 mV: 0%; -40 mV: 3%; 0 mV: 18%; 30 mV: 45%; 60 mV: 54%; 90 mV: 50% — [Yang 2026, Fig. 1G](https://doi.org/10.64898/2026.06.01.726307) ### Research papers using VADER1 (1) - [A red-emitting, genetically encoded indicator for two-photon voltage recording in vivo](https://doi.org/10.64898/2026.06.01.726307) — Yang S, McDonald AJ, Lu X, Villette V, Hakam N, Galdamez M, et al., bioRxiv 2026 (HEK293 cells, in vitro; Rat, cultured hippocampal neurons, in vitro; Mouse, visual cortex L2/3 and L5, in vivo) ## VARNAM Voltage indicator using opsin-FRET architecture with red fluorescent protein for improved tissue penetration. - Category: eFRET GEVI - Published: 2018-11-12 — [Nature Methods 2018](https://doi.org/10.1038/s41592-018-0188-7) - Derived from: [Ace2N-mNeon](https://gevibench.org/gevi/ace2n-mneon) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 558 nm, emission peak 592 nm (VARNAM) - Plasmid: [Addgene #115554](https://www.addgene.org/115554/) - Tags: Ace opsin, mRuby3, Red, FRET ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.85× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 3.0 / 2.8 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -10.8% (median of 3 measurements: −13.5%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.1% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 4.8% (median of 3 measurements: 5.3%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 3.6 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 30 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 7 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 3.04 ms, τ_off 2.75 ms at 22-25°C — [Kannan 2018, Table S1](https://doi.org/10.1038/s41592-018-0188-7) #### ΔF/F per 100 mV - -10.8%, 1P — [Liu 2021, Fig. 2c](https://doi.org/10.1038/s41557-021-00641-1) - -13.5%, 1P — [Kannan 2018, Fig. 2b](https://doi.org/10.1038/s41592-018-0188-7) - -17.9%, 1P — [Han 2023, Fig. 1B](https://doi.org/10.1126/sciadv.adi4208) #### ΔF/F per mV (subthreshold) - 0.104%/mV — [Abdelfattah 2023, Fig. S5E](https://doi.org/10.1016/j.neuron.2023.03.009) #### ΔF/F per action potential - 4.8%, 1P — [Kannan 2018, Fig. 3d](https://doi.org/10.1038/s41592-018-0188-7) - 5.3%, 1P — [Liu 2021, Fig. 3a](https://doi.org/10.1038/s41557-021-00641-1) - 8.4%, 1P — [Kannan 2018, Fig. 2f](https://doi.org/10.1038/s41592-018-0188-7) #### AP width (FWHM) - 3.6 ms at 500 Hz sampling, Drosophila, PPL1-α'2α2 dopaminergic neuron, in vivo, 1P, 25°C — [Kannan 2018, Fig. 6d](https://doi.org/10.1038/s41592-018-0188-7) #### Brightness comparisons - 2286× the brightness of Arch — [Monakhov 2020, Table 1](https://doi.org/10.1021/acschemneuro.0c00046) - 0.71× the brightness of Ace2N-mNeon — [Kannan 2018, Fig. 1j](https://doi.org/10.1038/s41592-018-0188-7) - 0.6× the brightness of Cepheid1b — [Han 2023, Fig. S5](https://doi.org/10.1126/sciadv.adi4208) - 2.32× the brightness of Cepheid1s — [Han 2023, Fig. S5](https://doi.org/10.1126/sciadv.adi4208) - 1× the brightness of VARNAM2 — [Kannan 2022, Fig. S11A](https://doi.org/10.1126/science.abm8797) #### Photobleaching - t75% = 164 s at 15.9 mW/mm², 1P — [Han 2023, Fig. S6A](https://doi.org/10.1126/sciadv.adi4208) - t50% = 368 s, 1P — [Kannan 2022, Fig. S11B](https://doi.org/10.1126/science.abm8797) - t75% = 70 s at 48 mW/mm², 1P — [Liu 2021, Ext. Fig. 4g](https://doi.org/10.1038/s41557-021-00641-1) - t75% = 66 s at 15 mW/mm², 1P — [Kannan 2018, Fig. S7a](https://doi.org/10.1038/s41592-018-0188-7) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -150 mV: 9%; -130 mV: 8%; -110 mV: 6.5%; -90 mV: 3.5%; -70 mV: 0%; -50 mV: -4%; -30 mV: -7.5%; -10 mV: -10.5%; 10 mV: -12.5%; 30 mV: -13.5%; 50 mV: -14% — [Kannan 2018, Fig. 2b](https://doi.org/10.1038/s41592-018-0188-7) ### Research papers using VARNAM (7) - [Fast, in vivo voltage imaging using a red fluorescent indicator](https://doi.org/10.1038/s41592-018-0188-7) — Kannan M, Vasan G, Huang C, Haziza S, Li JZ, Inan H, Schnitzer MJ, Pieribone VA, Nature Methods 2018 (HEK cells, cultured neurons, mouse cortex and hippocampus in vivo, Drosophila in vivo) - [A high-speed, bright, red fluorescent voltage sensor to detect neural activity](https://doi.org/10.1038/s41598-019-52370-8) — Beck C, Gong Y, Scientific Reports 2019 (HEK293T cells, cultured neurons) - [Screening and Cellular Characterization of Genetically Encoded Voltage Indicators Based on Near-Infrared Fluorescent Proteins](https://doi.org/10.1021/acschemneuro.0c00046) — Monakhov MV, Matlashov ME, Colavita M, Song C, Shcherbakova DM, Antic SD, Verkhusha VV, Knopfel T, ACS Chemical Neuroscience 2020 (HEK cells, cultured neurons) - [A far-red hybrid voltage indicator enabled by bioorthogonal engineering of rhodopsin on live neurons](https://doi.org/10.1038/s41557-021-00641-1) — Liu S, Lin C, Xu Y, Luo H, Peng L, Zeng X, Zheng H, Chen PR, Zou P, Nature Chemistry 2021 (Rat hippocampal neurons, cultured) - [Dual-polarity voltage imaging of the concurrent dynamics of multiple neuron types](https://doi.org/10.1126/science.abm8797) — Kannan M, Vasan G, Haziza S, Huang C, Chrapkiewicz R, Luo J, Cardin JA, Schnitzer MJ, Pieribone VA, Science 2022 (Mouse visual cortex and hippocampus in vivo, Drosophila in vivo) - [Sensitivity optimization of a rhodopsin-based fluorescent voltage indicator](https://doi.org/10.1016/j.neuron.2023.03.009) — Abdelfattah AS, et al., Neuron 2023 (HEK293 cells, cultured neurons) - [Bright and sensitive red voltage indicators for imaging action potentials in brain slices and pancreatic islets](https://doi.org/10.1126/sciadv.adi4208) — Han Y, Yang J, Li Y, Chen Y, Ren H, Ding R, Qian W, Ren K, Xie B, Deng M, Xiao Y, Chu J, Zou P, Science Advances 2023 (HEK293T cells, in vitro; rat hippocampal neurons, in vitro) ## VARNAM2 Second-generation red-shifted eFRET voltage indicator derived from VARNAM with improved voltage sensitivity for low-power in vivo imaging in behaving animals. - Category: eFRET GEVI - Published: 2022-11-04 — [Science 2022](https://doi.org/10.1126/science.abm8797) - Derived from: [VARNAM](https://gevibench.org/gevi/varnam) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 558 nm, emission peak 592 nm (VARNAM2) - Plasmid: [Addgene #195520](https://www.addgene.org/195520/) - Tags: Ace opsin, mRuby3, Red, FRET ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.85× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 0.95 / 1.2 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -19.1% (median of 2 measurements: −22.9%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.23% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 7.3% (median of 2 measurements: 8.15%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 5.3 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 1.7 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 3 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 0.95 ms, τ_off 1.21 ms at 22°C — [Kannan 2022, Table S1](https://doi.org/10.1126/science.abm8797) #### ΔF/F per 100 mV - -19.1%, 1P — [Kannan 2022, Table S1](https://doi.org/10.1126/science.abm8797) - -26.7%, 1P — [Han 2023, Fig. 1B](https://doi.org/10.1126/sciadv.adi4208) #### ΔF/F per action potential - 7.3%, 1P — [Kannan 2022, Fig. 1I](https://doi.org/10.1126/science.abm8797) - 9%, 1P — [Han 2023, Fig. 1C](https://doi.org/10.1126/sciadv.adi4208) #### AP width (FWHM) - 2.7 ms at 400 Hz sampling, Mouse, V1 VIP+ interneurons, awake, in vivo, 1P, 37°C — [Kannan 2022, Fig. 1I](https://doi.org/10.1126/science.abm8797) - 8 ms at 484 Hz sampling, cultured rat hippocampal neurons, in vitro, 1P — [Han 2023, Fig. 1D](https://doi.org/10.1126/sciadv.adi4208) #### Brightness comparisons - 1× the brightness of VARNAM — [Kannan 2022, Fig. S11A](https://doi.org/10.1126/science.abm8797) - 1.4285714285714286× the brightness of pAceR — [Kannan 2022, Fig. S11A](https://doi.org/10.1126/science.abm8797) #### Photobleaching - t75% = 421 s at 15.9 mW/mm², 1P — [Han 2023, Fig. S6A](https://doi.org/10.1126/sciadv.adi4208) - t50% = 552 s, 1P — [Kannan 2022, Fig. S11B](https://doi.org/10.1126/science.abm8797) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -150 mV: 17%; -130 mV: 14%; -110 mV: 11%; -90 mV: 5%; -70 mV: 0%; -50 mV: -4%; -30 mV: -10%; -10 mV: -14%; 10 mV: -18%; 30 mV: -21%; 50 mV: -23% — [Kannan 2022, Fig. 1D](https://doi.org/10.1126/science.abm8797) ### Research papers using VARNAM2 (3) - [Dual-polarity voltage imaging of the concurrent dynamics of multiple neuron types](https://doi.org/10.1126/science.abm8797) — Kannan M, Vasan G, Haziza S, Huang C, Chrapkiewicz R, Luo J, Cardin JA, Schnitzer MJ, Pieribone VA, Science 2022 (HEK cells, in vitro; Drosophila PPL1-α'2α2 dopaminergic neurons, in vivo; mouse hippocampus CA1 EC-projecting pyramidal neurons, in vivo) - [Imaging high-frequency voltage dynamics in multiple neuron classes of behaving mammals](https://doi.org/10.1016/j.cell.2025.06.028) — Haziza S, Chrapkiewicz R, Zhang Y, Kruzhilin V, Li J, Delamare G, Swanson R, Buzsáki G, Kannan M, Vasan G, Lin MZ, Zeng H, Daigle T, Schnitzer MJ, Cell 2025 (Mouse, visual cortex (pyramidal neurons) and hippocampus, in vivo; dual-cell-type TEMPO imaging with VARNAM2 in pyramidal cells and ASAP3 in PV cells) - [Prefrontal gamma oscillations engage dynamic cell type-specific configurations to support flexible behavior](https://doi.org/10.1101/2024.03.08.584173) — Phensy AJ, Hagopian LL, Costello CM, Haziza S, Ghenand O, Zhang Y, Schnitzer MJ, Sohal V, bioRxiv 2025 (Mouse, medial prefrontal cortex, in vivo; VARNAM2 expressed in PFC→MD projection neurons (dual-color with Ace-mNeon2 in PV interneurons)) ## Vega Photostable green eFRET GEVI built by inserting mBaoJin(3M) into the first extracellular loop of Ace2 rhodopsin, with Kv2.1 and ER2 targeting motifs for long-duration one-photon voltage imaging. - Category: eFRET GEVI - Published: 2025-06-01 — [bioRxiv 2025](https://doi.org/10.1101/2025.05.29.656768) - Derived from: [Cepheid1b](https://gevibench.org/gevi/cepheid1b) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 500 nm, emission peak 508 nm (Vega) - Tags: Ace opsin, mBaoJin, Green, FRET, Somatic targeting ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 6.80× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 1.3 / 3.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -33.1% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.5% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 17.1% (median of 2 measurements: 14.6%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 4.8 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 4.7 min | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.34 ms, τ_off 3.74 ms at 21-23°C — [Cao 2025, Fig. S2](https://doi.org/10.1101/2025.05.29.656768) #### ΔF/F per 100 mV - -33.1%, 1P — [Cao 2025, Table S2](https://doi.org/10.1101/2025.05.29.656768) #### ΔF/F per action potential - 17.1%, 1P — [Cao 2025, Table S2](https://doi.org/10.1101/2025.05.29.656768) - 12%, 1P — [Cao 2025, Fig. 3A](https://doi.org/10.1101/2025.05.29.656768) #### AP width (FWHM) - 4.8 ms at 400 Hz sampling, Mouse, thalamic neurons, acute brain slice, 1P, 34.5°C — [Cao 2025, Fig. 3C](https://doi.org/10.1101/2025.05.29.656768) #### Brightness comparisons - 2× the brightness of Ace2N-mNeon2 — [Cao 2025, Fig. 1B](https://doi.org/10.1101/2025.05.29.656768) - 8× the brightness of JEDI-1P — [Cao 2025, Fig. 1B](https://doi.org/10.1101/2025.05.29.656768) #### Photobleaching - t75% = 946 s at 30 mW/mm², 1P — [Cao 2025, Fig. 1D](https://doi.org/10.1101/2025.05.29.656768) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: 13%; -80 mV: 5%; -70 mV: 0%; -60 mV: -5%; -40 mV: -15%; -20 mV: -23%; 0 mV: -29%; 20 mV: -33%; 40 mV: -36%; 60 mV: -38%; 80 mV: -40%; 100 mV: -41% — [Cao 2025, Fig. 1C](https://doi.org/10.1101/2025.05.29.656768) ### Research papers using Vega (1) - [A photostable genetically encoded voltage indicator for imaging neural activities in tissue and live animals](https://doi.org/10.1101/2025.05.29.656768) — Cao C, Zhu R, Zhou S, Zhao Z, Lin C, Liu S, Peng L, Subach FV, Piatkevich KD, Zou P, bioRxiv 2025 (HEK293T cells; Rat, hippocampal neurons, in vitro; Mouse, thalamic acute brain slices, ex vivo; Mouse, pancreatic islets, ex vivo; Mouse, visual cortex, in vivo) ## Voltron Breakthrough chemigenetic GEVI that binds fluorescent dyes with exceptional brightness and photostability. - Category: Chemigenetic GEVI - Published: 2019-08-16 — [Science 2019](https://doi.org/10.1126/science.aav6416) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 534 nm, emission peak 554 nm (Voltron (JF525)) - Plasmid: [Addgene #119033](https://www.addgene.org/119033/) - Tags: Ace opsin, HaloTag ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 11.04× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 2.0 / 2.2 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -23% (median of 8 measurements: −23%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.21% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 6.16% (median of 3 measurements: 6.5%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 3 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 25 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 9 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.99 ms, τ_off 2.18 ms at 25°C — [Abdelfattah 2019, Table S3](https://doi.org/10.1126/science.aav6416) - τ_on 2 ms, τ_off 3.19 ms at 23°C — [Abdelfattah 2023, Fig. 2E](https://doi.org/10.1016/j.neuron.2023.03.009) #### ΔF/F per 100 mV - -23%, 1P, dye JF525 — [Abdelfattah 2019, Fig. 1E](https://doi.org/10.1126/science.aav6416) - -23%, 1P, dye JF525 — [Abdelfattah 2020, Fig. 2a](https://doi.org/10.1038/s41467-020-17322-1) - -18.5%, 1P, dye JF525 — [Hasseman 2022, Fig. 1](https://doi.org/10.25378/janelia.21534411) - -17.1%, 1P, dye JF585 — [Yang 2024, Fig. 1C](https://doi.org/10.1101/2024.02.02.578569) - -16%, 1P, dye JF503 — [Abdelfattah 2019, Fig. 1E](https://doi.org/10.1126/science.aav6416) - -18%, 1P, dye JF549 — [Abdelfattah 2019, Fig. 1E](https://doi.org/10.1126/science.aav6416) - -18%, 1P, dye JF585 — [Abdelfattah 2019, Fig. 1E](https://doi.org/10.1126/science.aav6416) - -8%, 1P, dye JF635 — [Abdelfattah 2019, Fig. 1E](https://doi.org/10.1126/science.aav6416) #### ΔF/F per mV (subthreshold) - 0.21%/mV (Voltron525 subthreshold slope 0.21%/mV ± 0.01%/mV in the −90 to −50 mV range (cultured neurons, n=8 cells), reported in the running main text of the Voltron2 paper as the comparator to Voltron2525 (0.54%/mV). Not a labeled figure panel (Fig. 2B is the F-V curve).) — [Abdelfattah 2023, Main text](https://doi.org/10.1016/j.neuron.2023.03.009) #### ΔF/F per action potential - 6.16%, 1P, dye JF525 — [Abdelfattah 2023, Fig. 2G](https://doi.org/10.1016/j.neuron.2023.03.009) - 6.5%, 1P, dye JF525 — [Piatkevich 2019, Ext. Fig. 5c](https://doi.org/10.1038/s41586-019-1641-1) - 6.5%, 1P, dye JF525 — [Hasseman 2022, Fig. 2](https://doi.org/10.25378/janelia.21534411) #### AP width (FWHM) - 3 ms at 985 Hz sampling, Cultured rat hippocampal neurons, uM Workstation whole-cell current clamp, single evoked AP (2 nA, 2 ms pulse), 1P, 23°C — [Abdelfattah 2023, Fig. 2F](https://doi.org/10.1016/j.neuron.2023.03.009) #### Brightness comparisons - 4× the brightness of Ace2N-mNeon — [Abdelfattah 2019, Fig. 1F](https://doi.org/10.1126/science.aav6416) - 5.2631578947368425× the brightness of HVI — [Liu 2021, Table S4](https://doi.org/10.1038/s41557-021-00641-1) - 1.6949152542372883× the brightness of Positron — [Abdelfattah 2020, Fig. 2b](https://doi.org/10.1038/s41467-020-17322-1) - 1.5384615384615383× the brightness of Voltron2 — [Abdelfattah 2023, Fig. 2H](https://doi.org/10.1016/j.neuron.2023.03.009) #### Photobleaching - t75% = 30.5 s at 25 mW/mm² (510/25 nm), 1P — [Piatkevich 2019, Ext. Fig. 5e](https://doi.org/10.1038/s41586-019-1641-1) - t75% = 61 s at ~23 mW/mm² (510/25 nm), 1P — [Abdelfattah 2019, Fig. 1H](https://doi.org/10.1126/science.aav6416) - t75% = 245 s at 14.7 mW/mm² (510/25 nm), 1P — [Abdelfattah 2023, Fig. 2I](https://doi.org/10.1016/j.neuron.2023.03.009) - curve only (did not reach 75% within the measured window) at 70–140 mW/mm² (DMD patterned, per-cell), 1P — [Abdelfattah 2023, Fig. S8d](https://doi.org/10.1016/j.neuron.2023.03.009) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -110 mV: 8%; -90 mV: 4.5%; -70 mV: 0%; -50 mV: -4.5%; -30 mV: -9%; -10 mV: -13.5%; 10 mV: -18%; 30 mV: -22.5%; 50 mV: -27% — [Abdelfattah 2019, Fig. 1E](https://doi.org/10.1126/science.aav6416) ### Research papers using Voltron (9) - [Bright and photostable chemigenetic indicators for extended in vivo voltage imaging](https://doi.org/10.1126/science.aav6416) — Abdelfattah AS, Kawashima T, Singh A, et al., Science 2019 (Mouse cortex L1, larval zebrafish, Drosophila, in vivo; HEK cells) - [High-fidelity estimates of spikes and subthreshold waveforms from 1-photon voltage imaging in vivo](https://doi.org/10.1016/j.celrep.2021.108954) — Xie ME, et al., Cell Reports 2021 (Mouse, somatosensory cortex layer 1, in vivo) - [VolPy: Automated and scalable analysis pipelines for voltage imaging datasets](https://doi.org/10.1371/journal.pcbi.1008806) — Cai C, et al., PLOS Computational Biology 2021 (Mouse cortex L1 and larval zebrafish tegmentum, in vivo) - [Single Photon Kilohertz Frame Rate Imaging of Neural Activity](https://doi.org/10.1002/advs.202203018) — Tian T, Yuan Y, Mitra S, et al., Advanced Science 2022 (Rat, hippocampal CA1, acute brain slices, Voltron-JF525) - [Voltage-Seq: all-optical postsynaptic connectome-guided single-cell transcriptomics](https://doi.org/10.1038/s41592-023-01965-1) — Csillag V, et al., Nature Methods 2023 (Mouse, periaqueductal gray (PAG), acute brain slices, Voltron-ST + JF585) - [All-optical voltage imaging-guided postsynaptic single-cell transcriptome profiling with Voltage-Seq](https://doi.org/10.1038/s41596-024-01005-y) — Csillag V, Noble JC, Calvigioni D, et al., Nature Protocols 2024 (Mouse, acute brain slices, Voltron-ST) - [Dynamic assemblies of parvalbumin interneurons in brain oscillations](https://doi.org/10.1016/j.neuron.2024.05.015) — Huang YC, et al., Neuron 2024 (Mouse, hippocampal CA1, PV interneurons, in vivo) - [Optical Recordings of Unitary Synaptic Connections Reveal High and Random Local Connectivity between CA3 Pyramidal Cells](https://doi.org/10.1523/JNEUROSCI.0102-25.2025) — Layous R, et al., Journal of Neuroscience 2025 (Rat, hippocampal CA3 pyramidal cells, acute brain slices, Voltron-ST + JF549) - [Voltage imaging reveals circuit computations in the raphe underlying serotonin-mediated motor vigor learning](https://doi.org/10.1016/j.neuron.2025.05.017) — Kawashima T, et al., Neuron 2025 (Larval zebrafish, serotonergic raphe (DRN), in vivo) ## Voltron2 Improved Voltron with enhanced sensitivity, retaining fast kinetics and photostability. - Category: Chemigenetic GEVI - Published: 2023-04-03 — [Neuron 2023](https://doi.org/10.1016/j.neuron.2023.03.009) - Derived from: [Voltron](https://gevibench.org/gevi/voltron) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 534 nm, emission peak 554 nm (Voltron2 (JF525)) - Two-photon compatible: yes - Plasmid: [Addgene #172909](https://www.addgene.org/172909/) - Tags: Ace opsin, HaloTag ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 7.18× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 4.0 / 5.5 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -34% (median of 5 measurements: −27%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.51% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 10.09% (median of 4 measurements: 12%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | 3.2 ms | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | 42 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 23 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.5 ms, τ_off 3.05 ms at 23°C — [Abdelfattah 2023, Fig. 2E](https://doi.org/10.1016/j.neuron.2023.03.009) - τ_on 3.96 ms, τ_off 5.53 ms at 25°C — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) #### ΔF/F per 100 mV - -34%, 1P, dye JF525 — [Abdelfattah 2023, Fig. 2B](https://doi.org/10.1016/j.neuron.2023.03.009) - -23%, 1P, dye JF525 — [Cao 2025, Fig. 1C](https://doi.org/10.1101/2025.05.29.656768) - -21.2%, 1P, dye JF525 — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) - -22%, 1P, dye JF585 — [Yang 2024, Fig. 1C](https://doi.org/10.1101/2024.02.02.578569) - -31%, 1P, dye JF525 — [Hasseman 2022, Fig. 1](https://doi.org/10.25378/janelia.21534411) #### ΔF/F per mV (subthreshold) - 0.54%/mV (Voltron2525 subthreshold slope 0.54%/mV ± 0.01%/mV in the −90 to −50 mV range (cultured neurons, n = 8 cells), an almost 3-fold higher slope than Voltron525 (0.21%/mV). Reported in the running main text; not a labeled figure panel (Fig. 3D is the synPSP sensitivity index d'/mV of Voltron2585, a different dye/metric).) — [Abdelfattah 2023, Main text](https://doi.org/10.1016/j.neuron.2023.03.009) - 0.48%/mV (Voltron2525-Kv subthreshold voltage-sensitivity slope ≈ 0.48 %/mV, read from the Fig. 5C comparison in the Hao et al. 2024 ASAP5 paper (soma-targeted Voltron2525-Kv, cultured rat hippocampal neurons), where the paper's primary sensor ASAP5-Kv is ≈ 0.83 %/mV. A different prep/metric from the origin-paper 0.54 %/mV entry above (that one is the −90→−50 mV subthreshold slope of un-targeted Voltron2525).) — [Hao 2024, Fig. 5C](https://doi.org/10.1016/j.neuron.2024.08.019) #### ΔF/F per action potential - 10.09%, 1P, dye JF525 — [Abdelfattah 2023, Fig. 2G](https://doi.org/10.1016/j.neuron.2023.03.009) - 12%, 1P, dye JF525 — [Liu 2025, Table S2](https://doi.org/10.1126/sciadv.ads1807) - 15%, 1P, dye JF525 — [Hasseman 2022, Fig. 2](https://doi.org/10.25378/janelia.21534411) - 12.3%, 1P, dye JF585 — [Yang 2024, Fig. 2B](https://doi.org/10.1101/2024.02.02.578569) #### AP width (FWHM) - 3.2 ms at 985 Hz sampling, Cultured rat hippocampal neurons, uM Workstation whole-cell current clamp, single evoked AP (2 nA, 2 ms pulse), 1P, 23°C — [Abdelfattah 2023, Fig. 2F](https://doi.org/10.1016/j.neuron.2023.03.009) - 7 ms at 484 Hz sampling, Rat, hippocampal neurons, in vitro, 1P, 25°C — [Yang 2024, Fig. 2B](https://doi.org/10.1101/2024.02.02.578569) - 0.85 ms at 3500 Hz sampling, Mouse, cerebellar granular-layer Golgi/glycinergic interneurons, in vivo, awake, Voltron2-ST552 (JF552), 2P — [Villette 2024, Fig. S9d](https://doi.org/10.1101/2024.11.15.623698) #### Brightness comparisons - 0.65× the brightness of Voltron — [Abdelfattah 2023, Fig. 2H](https://doi.org/10.1016/j.neuron.2023.03.009) #### Photobleaching - t75% = 307 s at 14.7 mW/mm², 1P — [Abdelfattah 2023, Fig. 2I](https://doi.org/10.1016/j.neuron.2023.03.009) - t75% = 83 s at 50 mW/mm², 1P — [Liu 2025, Fig. S7](https://doi.org/10.1126/sciadv.ads1807) - t75% = 77 s (extrapolated) at 46 mW/mm², 1P — [Hao 2024, Fig. S5E](https://doi.org/10.1016/j.neuron.2024.08.019) - curve only (did not reach 75% within the measured window) at 70–140 mW/mm² (DMD patterned, per-cell), 1P — [Abdelfattah 2023, Fig. S8d](https://doi.org/10.1016/j.neuron.2023.03.009) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -110 mV: 23%; -90 mV: 11%; -70 mV: 0%; -50 mV: -10%; -30 mV: -18%; -10 mV: -25%; 10 mV: -30%; 30 mV: -34%; 50 mV: -37% — [Abdelfattah 2023, Fig. 2B](https://doi.org/10.1016/j.neuron.2023.03.009) ### Research papers using Voltron2 (23) - [Sensitivity optimization of a rhodopsin-based fluorescent voltage indicator](https://doi.org/10.1016/j.neuron.2023.03.009) — Abdelfattah AS, et al., Neuron 2023 (Cultured neurons; flies, zebrafish, and mice, in vivo) - [Photophysics-informed two-photon voltage imaging using FRET-opsin voltage indicators](https://doi.org/10.1126/sciadv.adp5763) — Brooks FP, et al., Science Advances 2025 (Mouse, barrel cortex, in vivo, two-photon) - [Imaging neuronal voltage beyond the scattering limit](https://doi.org/10.1038/s41592-025-02692-5) — Chen TW, et al., Nature Methods 2025 (Mouse, hippocampus CA1, in vivo) - [Large-scale deep tissue voltage imaging with targeted-illumination confocal microscopy](https://doi.org/10.1038/s41592-024-02275-w) — Xiao S, et al., Nature Methods 2024 (Mouse, cortex, in vivo) - [Two-photon voltage imaging with rhodopsin-based sensors](https://doi.org/10.1016/j.neuron.2025.12.014) — Grimm C, et al., Neuron 2026 (Mouse, hippocampal slices; zebrafish larvae; mouse cortex, in vivo, two-photon) - [Orange/far-red hybrid voltage indicators with reduced phototoxicity enable reliable long-term imaging in neurons and cardiomyocytes](https://doi.org/10.1073/pnas.2306950120) — Liu Y, et al., PNAS 2023 (Rat, hippocampal neurons, in vitro; cardiomyocytes, in vitro) - [Miniaturized widefield microscope for high speed in vivo voltage imaging](https://doi.org/10.1364/BOE.576516) — Saladrigas CA, et al., Biomedical Optics Express 2025 (Mouse, visual cortex interneurons, in vivo) - [Voltage imaging with periodic structured illumination](https://doi.org/10.1364/BOE.573621) — Speed F, et al., Biomedical Optics Express 2025 (Mouse, somatosensory, visual, and motor cortex, in vivo, Voltron2-JF552) - [Relative phase of membrane potential theta oscillations between individual hippocampal neurons code space](https://doi.org/10.1101/2025.11.14.688496) — Athif M, et al., bioRxiv 2025 (Mouse, hippocampus CA1, in vivo) - [Dendritic excitations govern back-propagation via a spike-rate accelerometer](https://doi.org/10.1038/s41467-025-55819-9) — Park P, et al., Nature Communications 2025 (Mouse, hippocampus CA1 pyramidal neurons, acute brain slices, Optopatch-V (Voltron2-based)) - [A fast and responsive voltage indicator with enhanced sensitivity for unitary synaptic events](https://doi.org/10.1016/j.neuron.2024.08.019) — Hao YA, et al., Neuron 2024 (Rat, hippocampal neurons, in vitro) - [Fast dendritic excitations primarily mediate back-propagation in CA1 pyramidal neurons during behavior](https://doi.org/10.64898/2026.01.03.696606) — Lee BH, et al., bioRxiv 2026 (Mouse, hippocampus CA1 pyramidal neurons, in vivo, Voltron2-JF608) - [A dendrite-resolved, in vivo transfer function from spike patterns to dendritic Ca2+](https://doi.org/10.64898/2026.01.18.700189) — Wu X, et al., bioRxiv 2026 (Mouse, hippocampus CA2 pyramidal neurons, in vivo) - [A scalable, all-optical method for mapping synaptic connectivity with cell-type specificity](https://doi.org/10.1101/2025.06.25.661552) — Moya MV, et al., bioRxiv 2025 (Mouse, motor cortex, acute brain slices, Voltron2-JF585) - [Voltage dynamics of dendritic integration and back-propagation in vivo](https://doi.org/10.1101/2023.05.25.542363) — Wong-Campos JD, et al., bioRxiv 2023 (Mouse, barrel cortex L2/3, in vivo) - [High-speed multiplane confocal microscopy for voltage imaging in densely labeled neuronal populations](https://doi.org/10.1038/s41593-023-01408-2) — Weber TD, et al., Nature Neuroscience 2023 (Mouse, motor cortex, acute brain slices and in vivo, Voltron2-ST JF585) - [Fast and light-efficient remote focusing for volumetric voltage imaging](https://doi.org/10.1038/s41467-024-53685-5) — Bohm UL, Judkewitz B, Nature Communications 2024 (Zebrafish larvae, spinal cord, in vivo) - [All-optical reporting of inhibitory receptor driving force in the nervous system](https://doi.org/10.1038/s41467-024-53074-y) — Selfe JS, et al., Nature Communications 2024 (Mouse, hippocampal organotypic slices and somatosensory cortex L1, in vitro and in vivo, Voltron2-ST) - [Synchronous ensembles of hippocampal CA1 pyramidal neurons during novel exploration](https://doi.org/10.7554/eLife.96718) — Chen EL, et al., eLife 2025 (Mouse, hippocampus CA1 pyramidal neurons, in vivo, Voltron2-ST JF552) - [A novel rhodopsin-based voltage indicator for simultaneous two-photon optical recording with GCaMP in vivo](https://doi.org/10.1101/2024.11.15.623698) — Villette V, et al., bioRxiv 2024 (Rat, hippocampal neurons, in vitro; mouse, cerebellum Golgi cells, in vivo, two-photon, Voltron2-ST JF552) - [Positive-going hybrid indicators for voltage imaging in excitable cells and tissues](https://doi.org/10.1126/sciadv.ads1807) — Liu S, et al., Science Advances 2025 (HEK293T cells and rat hippocampal neurons, in vitro; Voltron2525 (JF525) characterized head-to-head as a comparator to HVI+ (kinetics/dynamic range/sensitivity Table S2, photobleaching Fig. S7)) - [Solaris: a panel of bright and sensitive hybrid voltage indicators for imaging membrane potential in cultured neurons](https://doi.org/10.1101/2024.02.02.578569) — Yang J, et al., bioRxiv 2024 (HEK293T cells and rat hippocampal neurons, in vitro; Voltron2585 (JF585) characterized as a comparator to the Solaris dye series (dynamic range, per-AP sensitivity, kinetics)) - [A photostable genetically encoded voltage indicator for imaging neural activities in tissue and live animals](https://doi.org/10.1101/2025.05.29.656768) — Cao C, et al., bioRxiv 2025 (HEK293T cells; Voltron2525 (JF525) measured as a comparator (dynamic range −27.5%/100 mV, Fig. 1C) to the Vega indicator) ## VSFP-Butterfly FRET-based voltage indicator with a novel 'Butterfly' topology sandwiching the voltage-sensing domain between two fluorescent proteins. - Category: VSD-FRET GEVI - Published: 2012-10-15 — [J. Neurophysiol. 2012](https://doi.org/10.1152/jn.00452.2012) - Derived from: [VSFP2.1](https://gevibench.org/gevi/vsfp2) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 516 nm, emission peak 633 nm (VSFP-Butterfly) - Two-photon compatible: yes - Plasmid: [Addgene #47978](https://www.addgene.org/47978/) - Tags: Ci-VSP, mCitrine/mKate2, FRET, Two-photon ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.74× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 7.7 / 90 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +6% (median of 2 measurements: +3.95%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.042% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 0.3% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 28 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 7.7 ms, τ_off 89.9 ms at 32-34°C — [Akemann 2012, Fig. 2E](https://doi.org/10.1152/jn.00452.2012) #### ΔF/F per 100 mV - +6%, 1P — [Mishina 2014, Table 1](https://doi.org/10.3389/fnmol.2014.00078) - +1.9%, 1P — [Akemann 2012, Fig. 3C](https://doi.org/10.1152/jn.00452.2012) #### ΔF/F per mV (subthreshold) - 0.042%/mV — [Akemann 2012, Fig. 3C](https://doi.org/10.1152/jn.00452.2012) #### ΔF/F per action potential - 0.3%, 1P — [Akemann 2012, Fig. 3D](https://doi.org/10.1152/jn.00452.2012) #### Brightness comparisons - 1.74× the brightness of EGFP — [doi:EC×QY: mCitrine EC=77000, QY=0.76 vs EGFP EC=56000, QY=0.60](EC×QY: mCitrine EC=77000, QY=0.76 vs EGFP EC=56000, QY=0.60) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -140 mV: -9%; -120 mV: -8%; -100 mV: -6%; -80 mV: -2%; -70 mV: 0%; -60 mV: 2%; -40 mV: 5%; -20 mV: 6%; 0 mV: 6%; 20 mV: 6%; 40 mV: 6%; 60 mV: 6% — [Akemann 2012, Fig. 2C](https://doi.org/10.1152/jn.00452.2012) ### Research papers using VSFP-Butterfly (28) - [Imaging neural circuit dynamics with a voltage-sensitive fluorescent protein](https://doi.org/10.1152/jn.00452.2012) — Akemann W, Mutoh H, Perron A, Park YK, Iwamoto Y, Knöpfel T, Journal of Neurophysiology 2012 (Mouse, somatosensory cortex layer 2/3, in vivo; hippocampus CA3, brain slices; PC12 cells, in vitro) - [Exploration of genetically encoded voltage indicators based on a chimeric voltage sensing domain](https://doi.org/10.3389/fnmol.2014.00078) — Mishina Y, Mutoh H, Song C, Knöpfel T, Frontiers in Molecular Neuroscience 2014 (Mouse, somatosensory cortex, in vivo; PC12 and HEK293T cells, in vitro) - [Two-photon voltage imaging using a genetically encoded voltage indicator](https://doi.org/10.1038/srep02231) — Akemann W, et al., Scientific Reports 2013 (Mouse, cortex layer 2/3, brain slices; mouse, somatosensory cortex, in vivo) - [Voltage imaging of waking mouse cortex reveals emergence of critical neuronal dynamics](https://doi.org/10.1523/JNEUROSCI.3474-14.2014) — Scott G, et al., Journal of Neuroscience 2014 (Mouse, cortex, in vivo) - [Imaging the awake visual cortex with a genetically encoded voltage indicator](https://doi.org/10.1523/JNEUROSCI.0594-14.2015) — Carandini M, et al., Journal of Neuroscience 2015 (Mouse, visual cortex, in vivo, awake) - [Validation of optical voltage reporting by the genetically encoded voltage indicator VSFP-Butterfly from cortical layer 2/3 pyramidal neurons in mouse brain slices](https://doi.org/10.14814/phy2.12468) — Empson RM, et al., Physiological Reports 2015 (Mouse, cortex layer 2/3, brain slices) - [Cortical entropy, mutual information and scale-free dynamics in waking mice](https://doi.org/10.1093/cercor/bhw200) — Fagerholm ED, et al., Cerebral Cortex 2016 (Mouse, cortex, in vivo) - [Transgenic mice for intersectional targeting of neural sensors and effectors with high specificity and performance](https://doi.org/10.1016/j.neuron.2015.02.022) — Madisen L, et al., Neuron 2015 (Mouse, cortex, transgenic Ai78(TITL-VSFPB) line, in vivo) - [Transgenic strategies for sparse but strong expression of genetically encoded voltage and calcium indicators](https://doi.org/10.3390/ijms18071461) — Song C, et al., International Journal of Molecular Sciences 2017 (Mouse, cortex layer 2/3, transgenic) - [Imaging of brain slices with a genetically encoded voltage indicator](https://doi.org/10.1007/978-1-4939-6810-7_5) — Quicke P, et al., Methods in Molecular Biology 2017 (Mouse, cortex layer 2/3, brain slices) - [Cortical signatures of wakeful somatosensory processing](https://doi.org/10.1038/s41598-018-30422-9) — Song C, et al., Scientific Reports 2018 (Mouse, somatosensory cortex, in vivo, awake) - [Effects of arousal on mouse sensory cortex depend on modality](https://doi.org/10.1016/j.celrep.2018.02.092) — Shimaoka D, et al., Cell Reports 2018 (Mouse, visual cortex; barrel cortex; auditory cortex, in vivo, awake) - [Optogenetic sensors in the zebrafish heart: a novel in vivo electrophysiological tool to study cardiac arrhythmogenesis](https://doi.org/10.7150/thno.26108) — van Opbergen CJM, et al., Theranostics 2018 (Zebrafish, heart, in vivo) - [Slow moving neural source in the epileptic hippocampus can mimic progression of human seizures](https://doi.org/10.1038/s41598-018-19925-7) — Chiang CC, et al., Scientific Reports 2018 (Mouse, hippocampal slices, in vitro) - [Single-neuron level one-photon voltage imaging with sparsely targeted genetically encoded voltage indicators](https://doi.org/10.3389/fncel.2019.00039) — Quicke P, et al., Frontiers in Cellular Neuroscience 2019 (Mouse, cortex layer 2/3, brain slices) - [In vitro testing of voltage indicators: Archon1, ArcLightD, ASAP1, ASAP2s, ASAP3b, Bongwoori-Pos6, BeRST1, FlicR1, and Chi-VSFP-Butterfly](https://doi.org/10.1523/ENEURO.0060-20.2020) — Milosevic MM, et al., eNeuro 2020 (Mouse, cortex, brain slices; HEK293 cells, in vitro) - [Subcellular resolution three-dimensional light-field imaging with genetically encoded voltage indicators](https://doi.org/10.1117/1.NPh.7.3.035006) — Quicke P, et al., Neurophotonics 2020 (Mouse, brain slices, in vitro) - [Population imaging discrepancies between a genetically-encoded calcium indicator (GECI) versus a genetically-encoded voltage indicator (GEVI)](https://doi.org/10.1038/s41598-021-84651-6) — Zhu MH, et al., Scientific Reports 2021 (Mouse, somatosensory cortex, brain slices) - [Studying synaptically evoked cortical responses ex vivo with combination of a single neuron recording (whole-cell) and population voltage imaging (genetically encoded voltage indicator)](https://doi.org/10.3389/fnins.2021.773883) — Jang J, et al., Frontiers in Neuroscience 2021 (Mouse, cortex, brain slices) - [Cortex-wide dynamics of intrinsic electrical activities: propagating waves and their interactions](https://doi.org/10.1523/JNEUROSCI.0623-20.2021) — Liang Y, Song C, Liu M, Gong P, Zhou C, Knöpfel T, Journal of Neuroscience 2021 (Mouse, cortex, in vivo, anesthetized, CaMK2A-tTA;chi-VSFP transgenic) - [Combining cortical voltage imaging and hippocampal electrophysiology for investigating global, multi-timescale activity interactions in the brain](https://doi.org/10.3390/ijms23126814) — Pedrosa R, et al., International Journal of Molecular Sciences 2022 (Mouse, cortex; hippocampus, in vivo, awake) - [Evoked cortical depolarizations before and after the amyloid plaque accumulation: voltage imaging study](https://doi.org/10.3233/JAD-220249) — Zhu MH, Jogdand AH, Jang J, Nagella SC, Das B, Milosevic MM, Yan R, Antic SD, Journal of Alzheimer's Disease 2022 (Mouse, cortex, brain slices, Alzheimer's disease model (APPswe/PS1dE9), chi-VSFP transgenic) - [Cortical correlates of psychedelic-induced shaking behavior revealed by voltage imaging](https://doi.org/10.3390/ijms24119463) — Buchborn T, et al., International Journal of Molecular Sciences 2023 (Mouse, cortex layer 2/3, in vivo, awake) - [Complexity of cortical wave patterns of the wake mouse cortex](https://doi.org/10.1038/s41467-023-37088-6) — Liang Y, Liang J, Song C, Liu M, Knöpfel T, Gong P, Zhou C, Nature Communications 2023 (Mouse, cortex, in vivo, awake, CaMK2A-tTA;chi-VSFP transgenic) - [Imaging of evoked cortical depolarizations using either ASAP2s, or chi-VSFP, or Di-4-Anepps, or autofluorescence optical signals](https://doi.org/10.31083/j.jin2206160) — Milicevic KD, et al., Journal of Integrative Neuroscience 2023 (Mouse, cortex, brain slices) - [Cortical networks relating to arousal are differentially coupled to neural activity and hemodynamics](https://doi.org/10.1523/JNEUROSCI.0298-23.2024) — Meyer-Baese L, et al., Journal of Neuroscience 2024 (Mouse, cortex, in vivo, awake) - [Ex vivo propagation of synaptically-evoked cortical depolarizations in a mouse model of Alzheimer's disease at 20 Hz, 40 Hz, or 83 Hz](https://doi.org/10.1038/s41598-024-74262-2) — Patel AA, Zhu MH, Yan R, Antic SD, Scientific Reports 2024 (Mouse, cortex, brain slices, Alzheimer's disease model (5xFAD), chi-VSFP transgenic) - [Psychedelic 5-HT2A agonist increases spontaneous and evoked 5-Hz oscillations in visual and retrosplenial cortex](https://doi.org/10.1038/s42003-025-09492-9) — White CM, Azimi Z, Staadt R, Song C, Knöpfel T, Jancke D, Communications Biology 2026 (Mouse, visual cortex; retrosplenial cortex, in vivo, awake) ## VSFP1 The first genetically encoded voltage indicator, establishing the VSFP architecture of pairing a voltage-sensing domain with a FRET fluorescent protein pair. - Category: VSD-FRET GEVI - Published: 2001-12-20 — [European Journal of Neuroscience 2001](https://doi.org/10.1046/j.0953-816x.2001.01617.x) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 435 nm, emission peak 529 nm (VSFP1) - Tags: CFP/YFP, FRET ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 0.74 / 0.74 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +1.8% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.018% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 1 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 0.74 ms, τ_off 0.74 ms at 25-28°C — [Sakai 2001, Fig. 3E](https://doi.org/10.1046/j.0953-816x.2001.01617.x) #### ΔF/F per 100 mV - +1.8%, 1P — [Sakai 2001, Fig. 3B](https://doi.org/10.1046/j.0953-816x.2001.01617.x) #### ΔF/F per mV (subthreshold) - 0.018%/mV (Linear F-V slope = 1.8 ± 0.1%/100 mV = 0.018 %/mV (Sakai 2001 Fig. 3B, r=0.99, n=11). VSFP1's response is linear across the physiological range (no saturation), so its subthreshold slope equals its per-100-mV dynamic range.) — [Sakai 2001, Fig. 3B](https://doi.org/10.1046/j.0953-816x.2001.01617.x) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -100 mV: -0.5%; -70 mV: 0%; -50 mV: 0.3%; 0 mV: 1.2%; 50 mV: 2.1%; 100 mV: 3%; 150 mV: 3.8% — [Sakai 2001, Fig. 3B](https://doi.org/10.1046/j.0953-816x.2001.01617.x) ### Research papers using VSFP1 (1) - [Design and characterization of a DNA-encoded, voltage-sensitive fluorescent protein](https://doi.org/10.1046/j.0953-816x.2001.01617.x) — Sakai R, Repunte-Canonigo V, Raj CD, Knöpfel T, European Journal of Neuroscience 2001 (HEK 293 cells, in vitro) ## VSFP2.1 VSFP variant tuned to operate near resting membrane potential. - Category: VSD-FRET GEVI - Published: 2007-05-09 — [PLoS ONE 2007](https://doi.org/10.1371/journal.pone.0000440) - Derived from: [VSFP1](https://gevibench.org/gevi/vsfp1) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 433 nm, emission peak 529 nm (VSFP2.1) - Tags: Ci-VSP, Cerulean/Citrine, FRET ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | — | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 15 / 75 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | +2.7% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.086% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | — | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 2 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 15 ms, τ_off 75 ms at 35°C — [Dimitrov 2007, Table 1](https://doi.org/10.1371/journal.pone.0000440) #### ΔF/F per 100 mV - +2.7%, 1P — [Dimitrov 2007, Fig. 3B](https://doi.org/10.1371/journal.pone.0000440) #### ΔF/F per mV (subthreshold) - 0.086%/mV (Maximal slope of the ΔR/R–V curve at V½ = 8.6%/100 mV = 0.086 %/mV (Dimitrov 2007 Table 1, VSFP2.1 at 35°C). VSFP2.1 was engineered (Ci-VSP R217Q) to place V½ (−68.4 mV) near the resting potential, maximizing near-rest voltage sensitivity — its defining feature. 1P.) — [Dimitrov 2007, Table 1](https://doi.org/10.1371/journal.pone.0000440) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -140 mV: -3%; -120 mV: -2.8%; -100 mV: -2.1%; -80 mV: -0.8%; -70 mV: 0%; -60 mV: 0.8%; -40 mV: 2%; -20 mV: 2.5%; 0 mV: 2.6%; 20 mV: 2.7%; 40 mV: 2.7% — [Dimitrov 2007, Fig. 3B](https://doi.org/10.1371/journal.pone.0000440) ### Research papers using VSFP2.1 (2) - [Engineering and characterization of an enhanced fluorescent protein voltage sensor](https://doi.org/10.1371/journal.pone.0000440) — Dimitrov D, He Y, Mutoh H, Baker BJ, Cohen L, Akemann W, Knöpfel T, PLoS ONE 2007 (PC12 cells (neuroendocrine), in vitro) - [Second and third generation voltage-sensitive fluorescent proteins for monitoring membrane potential](https://doi.org/10.3389/neuro.02.005.2009) — Perron A, Mutoh H, Akemann W, Ghimire Gautam S, Dimitrov D, Iwamoto Y, Knöpfel T, Frontiers in Molecular Neuroscience 2009 (PC12 cells (neuroendocrine), primary hippocampal neurons, in vitro) ## VSFP2.3 The first VSFP variant to achieve reliable in vivo cortical voltage imaging in transgenic mice. - Category: VSD-FRET GEVI - Published: 2008-06-25 — [PLoS ONE 2008](https://doi.org/10.1371/journal.pone.0002514) - Derived from: [VSFP2.1](https://gevibench.org/gevi/vsfp2) - Response polarity: positive-going (fluorescence increases on depolarization) - Spectrum: excitation peak 433 nm, emission peak 529 nm (VSFP2.3) - Plasmid: [Addgene #87948](https://www.addgene.org/87948/) - Tags: Ci-VSP, Cerulean/Citrine, FRET ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 1.74× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 49 / 70 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -8.3% (median of 2 measurements: −9.65%) | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.15% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 0.2% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 8 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 46.7 ms, τ_off 49.3 ms at 35°C — [Lundby 2010, Table 1](https://doi.org/10.1007/s00249-010-0620-0) - τ_on 72 ms, τ_off 70.6 ms at 30°C — [Lundby 2010, Table 1](https://doi.org/10.1007/s00249-010-0620-0) - τ_on 85.8 ms, τ_off 137 ms at 25°C — [Lundby 2010, Table 1](https://doi.org/10.1007/s00249-010-0620-0) - τ_on 51.6 ms, τ_off 91.6 ms at 35°C — [Mishina 2014, Table 1](https://doi.org/10.3389/fnmol.2014.00078) #### ΔF/F per 100 mV - -8.3%, 1P — [Mutoh 2009, Table 1](https://doi.org/10.1371/journal.pone.0004555) - +11%, 1P — [Mishina 2014, Table 1](https://doi.org/10.3389/fnmol.2014.00078) #### ΔF/F per action potential - 0.2%, 1P — [Akemann 2009, Main text](https://doi.org/10.1016/j.bpj.2009.02.046) #### Brightness comparisons - 1.74× the brightness of EGFP — [doi:Estimated from Citrine QY=0.76, EC=77000 vs EGFP QY=0.60, EC=56000, FPbase](Estimated from Citrine QY=0.76, EC=77000 vs EGFP QY=0.60, EC=56000) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -140 mV: -3.6%; -110 mV: -3.2%; -90 mV: -2.3%; -70 mV: 0%; -50 mV: 3.8%; -30 mV: 7.7%; -10 mV: 10.1%; 10 mV: 11%; 30 mV: 11.4%; 50 mV: 11.5%; 70 mV: 11.6% — [Mutoh 2009, Fig. 3B](https://doi.org/10.1371/journal.pone.0004555) ### Research papers using VSFP2.3 (8) - [Engineering of a Genetically Encodable Fluorescent Voltage Sensor Exploiting Fast Ci-VSP Voltage-Sensing Movements](https://doi.org/10.1371/journal.pone.0002514) — Lundby A, Mutoh H, Dimitrov D, Akemann W, Knöpfel T, PLoS ONE 2008 (PC12 cells, in vitro voltage clamp) - [Biophysical characterization of the fluorescent protein voltage probe VSFP2.3 based on the voltage-sensing domain of Ci-VSP](https://doi.org/10.1007/s00249-010-0620-0) — Lundby A, Akemann W, Knöpfel T, European Biophysics Journal 2010 (PC12 cells, in vitro voltage clamp + sensing current measurements at 25/30/35°C) - [Spectrally-resolved response properties of the three most advanced FRET based fluorescent protein voltage probes](https://doi.org/10.1371/journal.pone.0004555) — Mutoh H, Perron A, Dimitrov D, Iwamoto Y, Akemann W, Chudakov DM, Knöpfel T, PLoS ONE 2009 (PC12 cells, in vitro voltage clamp, spectral characterization at 35°C) - [Imaging brain electric signals with genetically targeted voltage-sensitive fluorescent proteins](https://doi.org/10.1038/nmeth.1479) — Akemann W, Mutoh H, Perron A, Rossier J, Knöpfel T, Nature Methods 2010 (Mouse, somatosensory cortex layer 2/3, in vivo + brain slices) - [Exploration of genetically encoded voltage indicators based on a chimeric voltage sensing domain](https://doi.org/10.3389/fnmol.2014.00078) — Mishina Y, Mutoh H, Song C, Knöpfel T, Frontiers in Molecular Neuroscience 2014 (PC12 and HEK cells, in vitro voltage clamp + mouse cortex in vivo) - [Comparative performance of a genetically-encoded voltage indicator and a blue voltage sensitive dye for large scale cortical voltage imaging](https://doi.org/10.3389/fncel.2015.00147) — Mutoh H, Mishina Y, Gallero-Salas Y, Knöpfel T, Frontiers in Cellular Neuroscience 2015 (Mouse, somatosensory cortex, in vivo anesthetized) - [Sensing Cardiac Electrical Activity With a Cardiac Myocyte-Targeted Optogenetic Voltage Indicator](https://doi.org/10.1161/CIRCRESAHA.117.306143) — Chang Liao ML, et al., Circulation Research 2015 (Mouse, heart cardiomyocytes and iPSC-derived cardiomyocytes, in vitro + ex vivo + in vivo) - [Electrotonic coupling of excitable and nonexcitable cells in the heart revealed by optogenetics](https://doi.org/10.1073/pnas.1611184114) — Quinn TA, et al., Proceedings of the National Academy of Sciences 2016 (Mouse, heart myocytes and non-myocytes, ex vivo Langendorff-perfused hearts) ## VSFP3.1 Third-generation Ci-VSP voltage sensor using a single Cerulean fluorescent protein, derived from VSFP2 by removing the FRET acceptor, achieving the fastest response kinetics reported among fluorescent protein-based voltage indicators at the time. - Category: VSD-FRET GEVI - Published: 2009-06-10 — [Front. Mol. Neurosci. 2009](https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/neuro.02.005.2009/full) - Derived from: [VSFP2.1](https://gevibench.org/gevi/vsfp2) - Response polarity: negative-going (fluorescence decreases on depolarization) - Spectrum: excitation peak 435 nm, emission peak 477 nm (VSFP3.1) - Plasmid: [Addgene #18951](https://www.addgene.org/18951/) - Tags: Ci-VSP, Cerulean, Single FP, Fast kinetics ### Headline values (as shown in the GEVIBench table) | Metric | Value | Definition | |---|---|---| | Brightness (B/B_EGFP) | 0.79× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. | | Kinetics τ_on / τ_off (ms) | 25 / NaN ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. | | ΔF/F per 100 mV | -1.3% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | ΔF/F per mV | 0.02% (estimated from the F–V curve) | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. | | ΔF/F per AP | 0.075% | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. | | AP width (FWHM, ms) | — | Full width at half maximum of the optical spike waveform. | | Photostability t75% @ 100 mW/mm² | — | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. | | Papers using it (N_used) | 5 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). | ### Measurements and sources #### Kinetics - τ_on 1.3 ms, τ_off — ms at 25°C — [Lundby 2008, Fig. 3C](https://doi.org/10.1371/journal.pone.0002514) - τ_on 25.3 ms, τ_off — ms at 35°C — [Perron 2009, Table 1](https://doi.org/10.1016/j.chembiol.2009.11.014) #### ΔF/F per 100 mV - -1.3%, 1P — [Perron 2009, Table 1](https://doi.org/10.1016/j.chembiol.2009.11.014) #### ΔF/F per action potential - 0.075%, 1P — [Akemann 2009, Fig. 9 C2](https://doi.org/10.1016/j.bpj.2009.02.046) #### Brightness comparisons - 0.79× the brightness of EGFP — [doi:Estimated from Cerulean EC=43000, QY=0.62 vs EGFP EC=56000, QY=0.60, FPbase](Estimated from Cerulean EC=43000, QY=0.62 vs EGFP EC=56000, QY=0.60) #### Fluorescence–voltage (F–V) curve ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -110 mV: 0.5%; -90 mV: 0.3%; -70 mV: 0%; -50 mV: -0.5%; -30 mV: -0.9%; -10 mV: -1.2%; 10 mV: -1.3%; 30 mV: -1.3%; 50 mV: -1.4%; 70 mV: -1.4%; 90 mV: -1.4% — [Lundby 2008, Fig. S3a](https://doi.org/10.1371/journal.pone.0002514) ### Research papers using VSFP3.1 (5) - [Second and third generation voltage-sensitive fluorescent proteins for monitoring membrane potential](https://doi.org/10.3389/neuro.02.005.2009) — Perron A, Mutoh H, Akemann W, Ghimire Gautam S, Dimitrov D, Iwamoto Y, Knöpfel T, Frontiers in Molecular Neuroscience 2009 (PC12 cells, hippocampal neurons, in vitro) - [Engineering of a genetically encodable fluorescent voltage sensor exploiting fast Ci-VSP voltage-sensing movements](https://doi.org/10.1371/journal.pone.0002514) — Lundby A, Mutoh H, Dimitrov D, Akemann W, Knöpfel T, PLoS ONE 2008 (PC12 cells, in vitro voltage clamp) - [Red-shifted voltage sensitive fluorescent proteins](https://doi.org/10.1016/j.chembiol.2009.11.014) — Perron A, Mutoh H, Launey T, Knöpfel T, Chemistry & Biology 2009 (PC12 cells, hippocampal neurons, in vitro) - [Effect of voltage sensitive fluorescent proteins on neuronal excitability](https://doi.org/10.1016/j.bpj.2009.02.046) — Akemann W, Lundby A, Mutoh H, Knöpfel T, Biophysical Journal 2009 (PC12 cells, computational model, in vitro) - [Membrane 'potential-omics': toward voltage imaging at the cell population level in roots of living plants](https://doi.org/10.3389/fpls.2013.00311) — Matzke AJ, Matzke M, Frontiers in Plant Science 2013 (Arabidopsis thaliana roots, in vivo (expressed the VSFP3.1_TagRFP color variant, plus VSFP2.3 and VSFP2.4; not the Cerulean VSFP3.1)) Generated 2026-10-12.