Fig. 4.

Monopolar 300-ns pulses are more efficient at cell killing than bipolar 300 + 300-ns pulses. U937 and CHO cells were exposed to trains of 2, 4, 8, or 12 pulses at 50 kV/cm (0.2 Hz). Cell viability was measured at 24 h and expressed as % to sham-exposed parallel controls. Mean ± SEM, N = 3–8. Higher cytotoxic efficiency of monopolar pulses is significant at least at p < 0.05 in all the groups (unpaired two-tailed t test)