Table 1.

In vitro characterization of RGECIs

Construct	Single AP max ΔF/F, %	τ_{on, ms}	τ_{off, ms}	τ_{bleach, s}
jRGECO1a	54 ± 10, n = 4 FOV, ∼30 cells/FOV	47.2 ± 1.0	443 ± 38	80.5 ± 5.1, n = 9 cells
R-CaMP2	31 ± 3, n = 3 FOV, ∼30 cells/FOV	26.3 ± 1.0	271 ± 20	61.9 ± 2.8, n = 8 cells
jRCaMP1a	17 ± 4, n = 4 FOV, ∼30 cells/FOV	61.2 ± 2.1	1600 ± 160	37.8 ± 2.1, n = 8 cells

Quantification of action potential responses in cultured neurons in Figure 1, and photobleaching kinetics in HEK293T cells. Action potential magnitudes and sensor kinetics are from 3 FOVs for R-CaMP2 and 4 FOVs for jRGECO1a and jRCaMP1a in separate dishes. Dishes were stimulated with 1 ms field stimulation pulses while imaging RGECI fluorescence at 50 Hz with 2.45 W/cm² 561 nm illumination. Photobleaching measurements were performed in HEK293T cells under 44 W/cm² 561 nm illumination (compared with 0.1 W/cm² used in slice imaging). All values are reported as mean ± SEM.