Homokaryons from animal and plant cells generated by electrofusion

A new apparatus was constructed which enables the use of the electrofusion method to obtain polynuclear cells of various mammalian cell lines, erythrocytes and plant protoplasts. This technique was applied to both suspensions and monolayers. Electrical and other physical parameters were monitored to find optimal conditions for mutual contact of cells (dielectrophoresis) and subsequent fusion. In the suspension technique, dielectrophoresis of mouse erythrocytes occurred at a field frequency of 20 kHz and a strength of 500 V.cm-1, whereas cultured mammalian cells and plant protoplasts required a frequency of 1-1.4 MHz and a strength of 250-800 V.cm-1. Fusion of cells was induced after the application of 1 to 10 high-voltage pulses of 1-5 kV.cm-1, 10-36 microseconds duration. After these high-voltage pulses were to the monolayer of mouse L cells, about 12% viable homokaryons were obtained.