Transmembrane potential measurements on mammalian cells using the voltage sensitive dye annine-6

Annine-6, a voltage sensitive dye, was used to evaluate the transmembrane potential sensitivity of different mammalian cell lines (KEK293, 22Rv1, and HeLa). Transmembrane potential was measured at different field strengths. To guarantee the comparability with theoretical charging models, the measurements have been performed well below the assumed critical value for incipient pore formation of approximately 1 kV/cm for a typical cell-diameter of 15 micrometer.A good agreement between theoretical predictions and data has been found considering the general shape of the measured curve, whereas discrepancies occurred considering the absolute amplitude.