Electroporation uses an electrical pulse for introducing a new species known as polar molecules into cells. The technique exploits the weak interactions between phospholipid bilayers that maintain the integrity of cell membranes. In a typical cell membrane, phospholipids are arrayed with the polar head groups pointing outward their hydrophobic tail groups pointing inward. It is an arrangement that impedes the passage of polar molecules that without some type of assistance, polar molecules cannot enter. When cells experience a controlled electric pulse, the phospholipid layer opens fully creating temporary physical channels that allow the molecules to enter automatically. Under the right conditions, the channels quickly close, returning the cell back into its original state, except that the cell now contains few foreign molecules.
In addition to the direct introduction of genes, electroporation facilitates the direct transfer of plasmids between cells or species, as for example, from the transformation of Bacteria to Yeast.
Extensive experimentation continues for the use of Electroporation for delivering medicines and vaccines directly to the cells of living organisms.
Electroporation is most commonly used to transfect cells transiently at the same time transfection is possible. In the biopharmaceutical industry, transient transfection enables the production of a few grams of protein for characterization and preclinical studies. In this application electroporation utilizing plasmids has proved to be very reliable and predictable. Electroporation similarly produces stably transfected cells provided that DNA is introduced in form by first treating it with a restriction enzyme.