LOTUS-V

First bioluminescent FRET-based voltage indicator, enabling excitation-free ratiometric imaging.

Category: Bioluminescent GEVI
Published: 2017-02-13 — Scientific Reports 2017
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
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
τ_on 119.12 ms, τ_off 73.17 ms at 23°C — Inagaki 2019, Fig. 1C

ΔF/F per 100 mV

+21% — Inagaki 2017, Fig. 2b

ΔF/F per action potential

2.8% — Inagaki 2019, Fig. 1D

AP width (FWHM)

11 ms at 1000 Hz sampling, Rat, hippocampal neurons, in vitro, 23°C — Inagaki 2019, Fig. 1D

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

Research papers using LOTUS-V (2)

Genetically encoded bioluminescent voltage indicator for multi-purpose use in wide range of bioimaging — 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 — 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)

Data and citation

llms.txt — summary for language models
llms-full.txt — every sensor in full (Markdown)
gevis.json — all values and measurements with sources (JSON)
gevis.csv — one row per sensor (CSV)

Cite GEVIBench as: Adam E. Cohen and Daozheng Gong (2026). Voltage imaging: A practical guide. Neuron. https://doi.org/10.1016/j.neuron.2026.08.002

Generated from the GEVIBench database on 2026-10-12.