Figure 4: DNA double strand break incidence and repair kinetics in MSCs exposed to 25 μM VP16. (a) Representative γ-H2AX staining (yellow) of Passage 6 MSCs exposed to VP16 for 24 hours followed by 0, 6, or 48 hours of recovery in fresh medium. γ-H2AX (Yellow) displays nuclear colocalization with DAPI (blue). (b) Percentage of MSCs displaying 10 or greater γ-H2AX foci at each time point at various passages. (c) Average number of γ-H2AX foci per cell at 6 hours of recovery time for passages 6 through 12. “NS” indicates no significant difference between any passage by One-Way ANOVA with Holm-Sidak Post Hoc test; -value > 0.05.