Highly uniform in-situ cell electrotransfection of adherent cultures using grouped interdigitated electrodes

Cell electrotransfection is an effective approach for transferring exogenous molecules into living cells by electric stimulation. The existing in-situ electrotransfection micro-devices for adherent cells exhibit the drawbacks of low transfection efficiency and low cell viability. An important reason for these drawbacks is the unequal exposure of cells to the electric field. It was found that cells growing directly below the energized electrodes experience a much lower electric field intensity when compared to the cells growing below the spacing area of the electrodes, resulting in low transfection with a strip-like pattern. Therefore, a new strategy for the in-situ electrotransfection of adherent cells growing in a standard 12-well plate is proposed in this study. By sequentially energizing electrodes arranged in a nested and non-contact manner, the cells were exposed to an overall equal intensity of the electric field, and thus a higher efficiency of transfection was achieved. The seven cell lines transfected using this method exhibited high transfection efficiency and high cell viability, demonstrating the potential for studying gene function.