Figure 5.

Detection of DNA single strand breaks by a comet assay. (A) MH-S cells were treated with PBS (blk), control NPs (NP), RuBpy-dye (Ru) or the Rubpy-doped NPs (Ru-NPs) for 2 h. For each treatment, one group of cells was subjected to 6 h irradiation and the other was incubated in the dark. The DNAs were evaluated by a comet assay and stained with SYBR Green. The DNA integrity was imaged with confocal microscope (arrow indicating significant DNA comet tail). (B) The comet tail length was defined as the distance between the leading edge of the nucleus and the end of the tail. The data are representative of three experiments.