Research Paper Volume 4, Issue 12 pp 952—965

Figure 1. Effect of exposure of TK6 cells to different presumed anti-aging drugs on the level of constitutive expression of γH2AX. Exponentially growing TK6 cells were untreated (Ctrl) or treated with the respective agents for 24 h at concentrations as shown. Expression of γH2AX in individual cells was detected immunocytochemically with the phospho-specific Ab (AlexaFluor647), DNA was stained with DAPI; cellular fluorescence was measured by flow cytometry. Based on differences in DNA content cells were gated in the respective phases of the cell cycle, as marked by the dashed vertical lines. The percent decrease in mean fluorescence intensity of the treated cells in particular phases of the cell cycle, with respect to the respective untreated controls, is shown above the arrows. Inserts present DNA content frequency histograms from the individual cultures. The dashed skewed lines show the background level, the mean fluorescence intensity of the cells stained with secondary Ab only.