Electroporation definition

Satyabhama, S., and Estonia, A. L. (1988) Short-term efficient expression of transfected DNA in human hematopoietic cells by electroporation Definition of parameters and use of chemical stimulators. DNA 7, 203-209. 

Iontophoresis by definition is the process of transport of ions into or through a tissue by the use of an applied potential difference across the tissue [52], Depending on the physicochemical characteristics of a molecular species, electrorepulsion is usually the primary mechanism of transdermal transport for ions, whereas electroosmosis and increased passive diffusion (as a result of the reduced barrier properties) are more prominent for neutral species [53]. In contrast, enhancement in flux for neutral or weakly charged species during electroporation arises predominantly from the reduced barrier properties of the membrane, whereas direct electrorepulsion is usually of secondary importance [25],... 

Plasmids, such as RNAi transgenes, can be introduced into ES cells by several methods, including electroporation (42). A drug-selectable marker is convenient to have on the same plasmid as the U6 or HI promoter-driven shRNA. This allows for selection of stable, clonal ES cell lines that may be assayed for levels of knockdown and the generation of embryos and mice. An important consideration for RNAi transgenesis in ES cells is the dominant nature of the teclmique. The disruption of genes required for ES cell self-renewal or smvival, by definition, does not produce ES cell clones with significant knockdown. The ES cells will either differentiate or die, but if clones are recovered, they likely have mild to moderate levels of knockdown. In these situations, an inducible RNAi system is required to circumvent this problem, as will be discussed next. 

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