Gene Transfer to Adherent Cells by in situ Electroporation with a Spiral Microelectrode Assembly

In this study, in situ electroporation is applied to adherent cell monolayers growing on standard multiwell plates. A new microelectrode assembly based on spiral geometry and fabricated using standard PCB tecnology with slight modifications is used. The system was tested in the electroporation of two different cell lines (CHO and HEK 293). A fluorescent probe was initially used to test the extent of permeabilization and adjust experimental conditions. Subsequently, plasmid DNA encoding green fluorescent protein (GFP) was transfered by electroporation. Together with these experiments, cell viability was studied. We show for permeabilization experiments up to 70 % of fluorescent cells detected in both cells lines. Successful gene electrotransfer was obtained with more than 9 % and 15 % for CHO and HEK 293 respectively. In this work we prove how our device can be used for electroporation of adherent cells under the same standard laboratory conditions as regular biochemical treatments.