Electroporation exploits the fact that high-voltage electrical fields can temporarily disrupt the structural integrity of cell membranes (1 ). When an electrical pulse is delivered to cells placed between two electrodes, pores develop in the membrane within 3 milliseconds (ms) and increase in size up to 120 nm by 20 ms (3 ). The presence of the pores is transient, and they reseal within a few seconds. During this brief window of time, it is possible to introduce a wide variety of macromolecules into mammalian tissue culture cells. Electroporation is broadly applicable to multiple cell types, highly efficient, reproducible, and appropriate for both transient and stable transfections.