( ...)Principles and applications of electrical cell fusion

Significance of cell fusion

Electrical cell fusion is an essential step in some of the most innovative methods in modern biology, such as the production of monoclonal antibodies, the cloning of mammals, and vaccination against cancer. Compared to the chemically induced cell fusion via polyethylene glycol (PEG), electrical cell fusion is a highly efficient method.
The process was discovered in 1978 by Zimmermann [1-3], who has initiated ongoing development ever since.

The principle of electrical cell fusion

First, the cells are brought into very close contact via dielectrophoresis. Unlike electrophoresis, in which direct current is applied in order to move molecules, dielectrophoresis uses highfrequency alternating current. In particles such as living cells, dipoles are induced which cause cells to align in such a way that they resemble a string of pearls which are in very close contact with each other.

A very short high-voltage pulse is then applied, which causes permeation of the cell membrane and the subsequent combining of the membranes. The cells then fuse. In order to stabilize the process, alternating voltage is then applied for a brief period.

The resulting formation is described as a heterokaryon because, although the outer cell membrane has fused, two or more cell nuclei are still present. The cell nuclei also fuse at a later point within the cell. In most cases, this results in a drastic reduction in the number of chromosomes in the nucleus.


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