Common commercial electroporation devices comprise parallel plate electrodes spaced millimeters apart with a volumetric capacity of hundreds of microliters. As a result, the conventional setup utilizes relatively large amounts of transfection reagents and DNA which can prohibitively expensive. The transfection efficiency and cell viability achieved by these setups also remain low due to their limitations in performing parametric optimizations via live monitoring. Some of the proposed approaches using microfluidic technology aim to counter these challenges by carrying out electroporation in enclosed microfluidic channels subject to fluid flow. However, this approach also comes along with several challenges, such as, a complex experimental setup containing fluidic channels, tubing and fluid pumps
A simple pin-plate electrode setup has been constructed in this study to reliably electroporate biological cells within droplets. The process constitutes temporary permeabilization of the plasma membrane by creating high electric fields at the tip of commercially available tapered tungsten electrodes. Subsequently, various electrical field frequencies were tested to quantify the insertion and release of dye molecules through the transient pores. Using optimized settings, we have also successfully managed to insert a plasmid to induce fluorescent protein expression, via a process referred to as transfection. The proposed design overcomes technological disadvantages of conventional cuvette-based electroporation, by creating a rapid sequentially addressable open-fluidic platform requiring small fluid volumes capable of handling multiple reagents.