Clotting of donor DNA during electroporation of prokaryotes

Abstract It has been found that strong electric fields ( E ≈ 7–13 kV/cm) normally used for electrotransformation and electrotransfection of prokaryotes drastically affect the electrophoretic mobility, susceptibility to various nucleases and biological activity of linear phage and circular plasmid DNAs. The effects are shown to be due to partial strand denaturation of DNAs at low ionic strength and strong electric fields which results in the formation of DNA clots. The results obtained are discussed in terms of their contribution to the understanding and explanation of some features of the electrotransformation method and evaluation of its limits.