DNA damage induced by DCQ+IR in EMT-6 cells. A. Representative images of comets induced by DCQ± IR in EMT-6 cells subjected to the alkaline comet assay. EMT-6 cells were treated with IR (10 Gy), 4 h of DCQ (10 μM), or in combination. Cells were directly collected after the treatment and subjected to the alkaline comet assay. Images were taken using a fluorescent microscope at 40× (oil immersion) magnification. The tail lengths of the comets observed by each treatment are proportional to the amount of DNA damage induced. B. The mean of the parameters (% DNA in comet's tail and tail moment) are shown in the graphs above. The histograms summarize the averages of two independent experiments ± SE and show the mean of the %DNA in comet's tail and tail moments. More than 50 cells per treatment were photographed and quantified using TriTek CometScore software. SE: standard error.