Measurement of the azimuthal membrane voltage distribution at by-2 protoplasts exposed to ns pulsed electric fields

Theoretical calculations of the azimuthal membrane voltage distribution of spherical cells in suspension exposed to an external electric field, based on isolating shell models, predict a sinusoidal angular dependency along an undisturbed membrane. These typical waveforms can be measured by pulsed laser fluorescence microscopy, while exposing the cells, stained with a voltage sensitive dye (ANNINE-6), to a rectangular electric field pulse, 500 ns after pulse onset and at low external electric field amplitude.