Electroporation - In this approach, transfection mixture containing cells and DNA is exposed for a very brief period (few milliseconds) to a very high voltage gradient (e.g., 4000-8000 V/cm).

This induces transient pores in the cell membranes through which DNA seems to enter the cells. Treatment of cells with colcemid before electroporation increases the frequency of transfection. Linearized DNA is far more efficient in transfection than circular supercoiled DNA.