Enhancement of an electroporation system for gene delivery using electrophoresis with a planar electrode.

In this paper a new electroporation (EP) system is developed, which includes an EP microchip and a logic circuit, which combined with electrophoresis (ES), can provide site-specific enhancement of gene concentration. In this ES-EP microchip, an arc planar electrode provides the ES function for DNA attraction, and interdigitated array electrodes provide appropriate electric fields for the EP on the chip surface. In addition, the adherent cells can be manipulated in situ without detachment of the ES-EP microchip, which performs the "Lab on a chip". Experimental results have shown that the efficiency of gene transfection with an attracting-electric field (35.89%) becomes much higher than that without an attracting-electric field (16.62%). Cell numbers as low as 10(4) cells, and DNA as little as 4 microg are sufficient for evaluating the phenotypic effects following the over-expression of the introduced genes on the ES-EP microchip. The proposed system has the advantages of portability, cost-effectiveness, a high transfection rate and ease of operation.