Skip to main content
. 2017 Nov 27;7:16372. doi: 10.1038/s41598-017-16142-6

Figure 2.

Figure 2

Symmetrical BP nsEPs that double the energized time of the front nsEP exhibit bipolar cancellation (BPC). (a) Representative differential interference contract (DIC) and confocal micrographs of Chinese Hamster Ovarian-K1 (CHO-K1) cells exposed to ↑300, ↑600, or ↑900 UP nsEPs, and symmetrical ↑300↓300, ↑600↓600, and ↑900↓900 BP nsEPs. The confocal micrographs represent YO-PRO®-1 fluorescence at baseline and 30 s post the nsEP exposure; scale bar 10 µm. (b) Quantitative assessment of YO-PRO®-1 uptake following exposure to UP and symmetrical BP nsEPs. In the plot, we evaluate YO-PRO®-1 uptake from UP nsEPs, and BP nsEP exposures that exhibit equivalent pulse durations (i.e. ↑300 ns vs. ↑300↓300 ns). As a control, we also measured YO-PRO®-1 uptake from UP nsEP exposures that have the same total energized time as the BP nsEPs (i.e. ↑1,200 ns vs. ↑600↓600 ns). Quantitative statistics- nsEP exposure, cells (N, cells): Sham (11,130), ↑300 (11,146), ↑600 (11,151), ↑900 (11,123), ↑1,200 (8,93), ↑1,800 (8,107), ↑300↓300 (11,129), ↑600↓600 (11,141), and ↑900↓900 (11,133). Statistical analysis of YO-PRO®-1 uptake 30 s post the nsEP exposure was determined with an unpaired two-tailed t-test, alpha = 0.05, p < 0.0001; (c,d) Temporal profile of YO-PRO®-1 uptake for 10 s following exposure to symmetrical BP nsEPs, and UP nsEPs. The zero point on the x-axis marks baseline YO-PRO®-1 fluorescence, and the black arrow head labels delivery of the nsEP. Nanosecond electric pulse exposures with similar temporal profiles are distinguished in gray to enhance contrast between the data sets.