Figure 5. Repair, but not initiation, of DSBs is more rapid in IRP1- cells.

Panel a: the increase in the number of foci-positive cells (those containing greater than 10 per nucleus) versus control and 2 Gy irradiated cells were scored at 30 m and 4 h post-IR and are plotted as percent foci-positive at 4 h post-IR versus 30 m. Data are mean +/− SEM from two independent experiments stained simultaneously. Exactly 500 cells were scored per sample. The paired t-test p-value was 0.07. Panel b: cells were irradiated with 0 or 4 Gy gamma rays and immediately assayed for DSB formation by the neutral comet assay. Whiskers represent the 1^st and 99^th percentiles, and means are indicated by ‘+’ (*** = p<0.001).