Figure 6

Image-processing methodology to compute the cumulative fluorescence intensity along the channel and enable rapid visual identification of the location of electroporated cells.

(a) The cumulative intensity CI at a point (indicated by the black arrow) is defined as the sum of the red shaded pixel values. In this figure, the black “Background” curve is virtually indistinguishable from the red “Before” curve. (b) The adjusted cumulative intensity CI’ is the same as in (a) but with the background subtracted to accurately determine the location of the onset of electroporation along the channel, which is indicated with a red star in both subfigures. This figure allows visual identification of the onset of electroporation-induced fluorescence enhancement and agrees with the quantitative findings of the KS test. Panels (c,d) are analogous to (a,b) for a case of C. glutamicum subjected to a 1-ms 2-kV voltage pulse.