J161044 Development of a micro fluidic device for visualization of mass transfer through cell membranes induced by electroporation

Abstract

In this study, we investigated the trans-membrane dynamics of macromolecules by real-time visualization in an on-chip electroporation using field focusing. The device for the on-chip electroporation consisted of two parallel microchannels that are connected through 37 micro-orifices for field focusing and cell trapping. The micro-orifice embedded in a vertical wall of the microchannel was 3.67 μm in width, 11.0 μm in height and 4.0 μm in length. HeLa cells stained with calcein were trapped at the micro-orifices by suction from one microchannel and buffer solution including ethidium homodimer was injected into the other. Then, pulsed voltages, which were 10 V high and 1 ms long, were applied every 6 s for 20 min to electrodes on a bottom wall of microchannels. The change of the fluorescence intensities between t = 0 min and 30 min indicated the successful pore formation by applying pulsed voltages. By analyzing the time course data of the fluorescence intensity, we discussed the detailed mass transfer through the cell membrane.