Manipulation of cell volume and membrane pore comparison following single cell permeabilization with 60- and 600-ns electric pulses

► We compared membrane nanopores produced by 60- and 600-ns electric pulses. ► Nanopore opening caused cell volume changes and propidium uptake. ► Nanopore size was probed by different molecular size osmolates. ► Unexpectedly, we found that pore size profiles after 60- and 600-ns pulses are similar. ► However, 600-ns pulses opened a small fraction of larger pores.