Research Paper Volume 8, Issue 10 pp 2449—2462

Figure 5. Temporal kinetics of the formation of the persistent DNA damage response foci induced by activation of miniSOG or tKR. (A-B) HeLa cells that express H2B-miniSOG (A) or H2B-tKR (B) were synchronized in S phase, illuminated with blue (465-495 nm, 65 mW/cm², 5 min) or green (540-580 nm, 200 mW/cm², 15 min) light, allowed to recover for the indicated time intervals (0, 3, 6 and 24 hr). Histone γH2AX was analyzed by indirect immunofluorescence or WB. Negative control represents the cells that were synchronized but not light illuminated; positive control represents the cells treated with DNA topoisomerase II inhibitor etoposide (VP16; 10 µg/ml, 1 hr). The DNA was stained with DAPI. Scale bar: 20 μm.