Ratiometry for improving the signal-to-noise with the red-shifted voltage dye di-4ANBDQBS

Abstract

Voltage-sensitive fluorescent dyes allow non-invasive recording of action potentials in single cells. These experiments often have low signal-to-noise ratios (SNR). To improve SNR, ratiometric fluorescence methods have been utilized. In these studies, we used di-4-ANBDQBS (Cytovolt1), a far-red-shifted voltage-sensitive dye with a stable signal that works through the Stark effect. HEK cells were loaded with CytoVolt1 that was excited at 528 nm using our optical system. Fluorescence emission was measured at 720 nm with a long pass filter and 655 nm with a bandpass filter, corresponding to opposite slope regions of the emission spectrum.