Fig. 1. Optimization of pulse conditions for electroporation. P.P., poring pulse; T.P., transfer pulse. The number of transformants was assessed by manipulating the voltage of the poring
pulse (P.P.), the transfer pulse (T.P.) and frequency of the discharge transfer pulse. Measured conductance is shown (KΩ). The sample mixture was pre-incubated at room temperature
(A) or on ice (B) before electroporation. Transformation efficiency was calculated as CFU (×105)/μg plasmid DNA electroporated using a cuvette with a 1 mm gap. Data are means ±
SD of values from three independent experiments with assays in duplicate.