ELECTROTRANSFORMATION OF BACTERIA BY PLASMID DNA - EFFECT OF SERIAL ELECTROPORATOR RESISTOR

Electroporation is a method widely used for the delivery of foreign DN A into plant, animal, and bacterial cell. We studied the influence of serial electroporator resistors (22 Omega, 330 Omega, and 510 Omega) o n electroporation parameters (electrotransformation efficiency and fre quency). Bacteria of Salmonella typhimurium LB 5000 and DNA of plasmid pUC19 were used as a source of cells and DNA, respectively. The highe st transformation frequency (number of transformants/number of survive d cells) was achieved with the 22 Omega serial resistor; the highest t ransformation efficiency (number of transformants/mu g DNA) was achiev ed with the 330 Omega serial resistor. For the relationship between th e number of transformed cells (n(t)) and the concentration of DNA (rho ) the equation In n(t) = a - b{rho} + d In{rho} (where a, b, d are con stants) was used. It was shown that the dependence of n(t) vs. rho may be influenced by a serial electroporator resistor, too.