Electrofusion of Penicillium protoplasts after dielectrophoresis

The protoplast fusion of auxotrophic Penicillium mutats after dielectrophoretic cell contact and rectangular field pulses (4,2 kV/cm, 25 μs) was microscopically observed in a microchamber consisting of two vapour-plated chromium electrodes on a microslide (gap between the electrodes of about 150 μm). The conditions for protoplasting of Penicillium and for electrofusion are described. Isolation of viable fusion products was realized.