The Duration of Cell-Cell Contacts Influences on Final Electrofusion Yields

Abstract

High voltage electric pulses permeabilize cell membranes. The phenomenon is known as electroporation. Permeabilized cell membrane is fusogenic and can fuse to other fusogenic membrane in close contact - the process is termed electrofusion. In this study we investigate how the duration of cell membrane contacts affects final electrofusion yield determined by dual color fluorescence microscopy. Contacts between cells were established by dielectrophoresis or by modified adherence method. The duration of the contact was 30 or 60 seconds for dielectrophoresis or several minutes for modified adherence method. The duration of cell contact affected final fusion yield; 30 seconds duration of dielectrophoresis resulted in 2.1 ± 0.7 % of fused cells, 60 seconds of the dielectrophoresis almost doubled the yield of fused cells (3.5 ± 0.9) and the highest yield of fused cells 8.4 ± 1.1 % was obtained by modified adherence methods. Since electric field parameters for electroporation were chosen in order to ensure high cell permeabilization in all electrofusion protocols we believe that the duration of the established cell-cell contacts is the parameter correlating with fusion yield. Our results suggest that the quality of contacts between cells correlate with the duration of established contacts.