Figure 2
From: A high-speed, bright, red fluorescent voltage sensor to detect neural activity
HEK293T cells expressing Ace-mScarlet exhibit high voltage sensitivity and brightness under whole-cell patch clamp. (a) Optical response of HEK293T cells transfected with Ace-mScarlet in response to a series of step voltages. We held HEK293T cells at –65 mV at the start of each sweep and applied command voltages ranging from −70 mV to +150 mV relative to the baseline voltage. (b) The peak fluorescence response of Ace-mScarlet decreases nearly linearly as a function of membrane voltage (mean ± s.d.). (c) The peak fluorescence response to a +100 mV step (from −70 mV to +30 mV) vs. brightness for HEK cells expressing Ace-7aa-mScarlet and Ace-8aa-mScarlet (n = 52 cells), Ace2N-mNeon (n = 23 cells), VARNAM (n = 42 cells), and FlicR1 (n = 30 cells). Ace-7aa-mScarlet and Ace-8aa-mScarlet exhibited the highest SNR of all red GEVIs tested (points and error bars are mean ± s.e.m.). Dashed lines represent SNR isocontours (Methods).
