Fig. 2
Flow cytometric analysis of phosphatidylserine (PS) externalisation. NP69 cells were either left untreated or treated with 100 μM of H2O2 for 16 and 24 h while HK1 cells were either left untreated or treated with 50 μM for 4 and 8 h. Cells treated with CPT was included as a positive control. The percentage of cells showing PS externalisation was determined in H2O2-treated NP69 cells (a i) and HK1 cells (b i). Means and SD of three independent experiments performed in duplicate are shown. Data are expressed as fold change normalised to untreated control. *p < 0.01, **p < 0.001 (Student’s t test). The representative dot plot diagrams indicating the apoptotic populations of (a ii) H2O2-treated NP69 cells and (b ii) H2O2-treated HK1 cells are shown. The lower left quadrants indicate healthy cells; the lower right quadrants indicate cells in early apoptosis; the upper right quadrants indicate cells in late apoptosis and necrosis