The term electroporation defines the reversible permeabilization of the cellular plasma membrane by means of a short-term but strong electric field (app. 1 kV/cm). This short-term permeabilization allows those hydrophilic molecules and ions to enter the cell interior that are normally excluded from there due to their hydrophilic nature by the membrane diffusion barrier. Electroporation has been successfully applied in the past to introduce all kinds of exogeneous molecules into the cells. Of greatest importance and relevance is the introduction of recombinant DNA.
Electroporation is most often performed with cells in suspension. In situ electroporation means electroporation of cells grown on goldfilm electrodes as used in ECIS. Thus, the cells can be loaded with exogeneus molecules without being detached from their growth substrate (see image on the right). Moreover, in situ electroporation is combined with impedimetric monitoring so that the response of the cells after introducing any kind of xenobiotic can be followed online. We use this combination of in situ electroporation and ECIS to study and analyze the effects of exogeneous molecules like small organic probes, peptides, antibodies, enzymes and DNA / RNA when they become active inside the cells.
Being a member of the DFG Priority Program SPP1313 we also study the biological response of nanoparticles when they are introduced into the cytoplasm of animal or human cells by in situ electroporation.