DiSBAC10 is a voltage-sensitive fluorescent probe used to study cell membrane electrical activity in FRET assays. In a resting polarized cell, DiSBAC10 resides on the outer leaflet of the membrane where it accepts photons from excited fluorescein-labeled proteins and re-emits the photons at a higher wavelength. Depolarization of the cell causes rapid translocation of DiSBAC10 to the inner leaflet of the membrane, thereby increasing the distance between fluorophores and reducing the FRET signal.