Characterizing the Radioresponse of Pluripotent and Multipotent Human Stem Cells
Figure 5
Repair of DNA double-strand breaks (DSB) in irradiated hES cells.
The repair kinetics of DNA DSBs was monitored by the formation and removal of γ-H2AX nuclear foci (green) in cells counterstained with the nuclear dye DAPI (blue, A–E). Immunocytochemical analysis of hESCs exposed to 5 Gy irradiation over a 6 h interval showed typical yields of γ-H2AX nuclear foci from 0.5–2 h (B, C and D) as compared to 0 Gy controls (A). The number of DSBs dropped rapidly after 2 h (E) indicating functional DSB repair. Peak yields of γ-H2AX foci occurred at 2 h before falling to baseline levels at 6 h post-irradiation (F). Data expressed as the Mean ± S.E.M. of 3–6 independent observations. Scale bars, 5 µm in A–E.
