ab2893 staining γH2A.X in HeLa cells treated with CPT 11 (Irinotecan) (ab141107), by ICC/IF. Increase of γH2A.X nuclear expression correlates with increased concentration of CPT 11 (Irinotecan), as described in literature.The cells were incubated at 37°C for 6 hours in media containing different concentrations of ab141107 (CPT 11 (Irinotecan)) in DMSO, fixed with 100% methanol for 5 minutes at -20°C and blocked with PBS containing 10% goat serum, 0.3 M glycine, 1% BSA and 0.1% tween for 2h at room temperature. Staining of the treated cells with ab2893 (5 µg/ml) was performed overnight at 4°C in PBS containing 1% BSA and 0.1% tween. A DyLight 488 anti-rabbit polyclonal antibody (ab96899) at 1/250 dilution was used as the secondary antibody. Nuclei were counterstained with DAPI and are shown in blue.