ab13847 staining active caspase 3 in A549 cells treated with quercetin (ab120247), by ICC/IF. Increase in active caspase 3 expression correlates with increased concentration of quercetin, as described in literature.The cells were incubated at 37°C for 6h in media containing different concentrations of ab120247 (quercetin) 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 ab13847 (1 µg/ml) was performed overnight at 4°C in PBS containing 1% BSA and 0.1% tween. A DyLight 488 goat anti-rabbit polyclonal antibody (ab968999) at 1/250 dilution was used as the secondary antibody. Nuclei were counterstained with DAPI and are shown in blue.