FIGURE 3.

NER-dependent DSB formation in quiescent human cells. A, G₀-arrested SuSa/T-n cells were irradiated with the indicated doses of UV and incubated for 1 h. The cells were processed according to the manufacturer's instructions for the Comet assay kit (Trevigen), and tail moment was calculated using a CometScore^TM program (TriTek Corp.). The mean values of tail moment with standard deviations were plotted as histograms. The statistical differences were determined by Student's t test. B and C, G₀-arrested SuSa/T-n or XP3OS/T-n cells were irradiated with 20 J/m² of UV and incubated for 1 h. DSB formation was analyzed by the neutral comet assay as described above. The representative images and quantitative data from three independent experiments were shown in B and C, respectively.