<p><b>Copyright information:</b></p><p>Taken from "Electroporator with automatic change of electric field direction improves gene electrotransfer "</p><p>http://www.biomedical-engineering-online.com/content/6/1/25</p><p>BioMedical Engineering OnLine 2007;6():25-25.</p><p>Published online 2 Jul 2007</p><p>PMCID:PMC1941843.</p><p></p>luence of electric field protocols: single polarity (a), both polarities (b), orthogonal single polarity (c) and orthogonal both polarities (d). Black areas represent regions of permeabilized membrane where DNA interacts with cell membrane