Fig. 2. Comparative analysis of _m loss in non-irradiated mitochondria and death indications in cells with either filamentous or punctate mitochondria. (A) Percentage of cells showing high _m (detected by Rh123 and visualised by confocal microscopy) following various treatments. Cells were treated with CCCP (or not treated), and then allowed to recover for 60 minutes in CCCP-free medium. Cells were then loaded with Rh123 and/or CMXRos before irradiation of about half the mitochondrial area in the perceptible section of the cell. The number of cells analysed under each set of conditions is indicated above each bar. (B) Percentage of irradiated cells showing cyt c release, PS exposure, and PI uptake between 30 and 120 minutes after irradiation, either containing filamentous mitochondria in otherwise untreated cells (filled bars; n=19) or punctate mitochondria in cells treated with CCCP and allowed to recover (open bars; n=16). Cells loaded with CMXRos (200 nM) were subjected to partial irradiation, then stained with annexin V conjugated to Alexa Fluor 488 and PI, followed by visualisation with confocal microscopy before fixing and staining with anti-cytochrome c antibody. There was no significant difference between the filamentous untreated reference group and punctate CCCP-treated group in all categories (P>0.1) as assessed by chi-squared contingency test.