In your Screen Quest membrane potential assays, what does an increase in fluorescence signal intensity represent? Are your membrane potential indicators positively charged compounds?

No, the membrane potential sensors provided in our Screen Quest™ Membrane Potential assays are not positively charged compounds. These sensors are predominantly neutral with some negatively charged forms present in the buffer. This allows the sensors to move freely in and out of the cells.

When the cell membrane depolarizes (becomes more positive inside), more of the sensor will enter the cell, thereby increasing the fluorescence signal intensity.