(A) cell electroporation and viability monitoring chip using a single channel with multiple electric field zones

Abstract

This thesis presents the cell electroporation (EP) and viability monitoring chips using a single channel with multiple electric field zones to find the optimum cell EP and viability conditions for stable cell transfection. The previous chips utilize one cell chamber with integrated multiple electrodes or multiple parallel microchannels with a pair of external electrodes to form multiple electric fields, thus resulting in complex structure. Therefore, we present two different types of single-microchannel cell EP and viability monitoring chips using the multiple electric field zones generated by a pair of external electrodes across stepwise (prototype S) and tapered (proto-type T) channel widths; thus making it possible to find the optimum cell EP rate and viability conditions for stable cell transfection. The present cell EP rate and viability monitoring chips have a single microchannel of stepwise (proto-type S) and tapered (prototype T) widths between an inlet and an outlet port. After seeding cells in the micro-channel, we supplied a pulse signal to the electrodes plugged in the inlet and outlet ports; generating multiple electric field zones along the microchannel by channel width change in a single channel. The stepwise widths of prototype S were designed as 200, 222, 250, 286, and 334$\mu$m so that 5 discrete electric fields (0.3, 0.35, 0.4, 0.45, 0.5kV/cm) are generated in the single channel at the supplied voltage of 340V. The tapered widths of prototype T were designed to change from 200$\mu$m to 334$\mu$m so that continuous electric field (0.3~0.5kV/cm) is formed at the voltage of 319V. And then, we observed the EP rate and viability of cells in the multiple electric field zones of the single channel by staining the cells with Propidium Iodide and Calcein AM, respectively. The present cell EP and viability monitoring chips were fabricated by PDMS molding process. In the experimental study, we used H23 and A549 human lung cancer cell lines to charact...