Immunofluorescent analysis of Phospho-Chk2 pThr68 (green) in HeLa cells either left untreated (left panel) or treated with 25 µg/mL anisomycin for 30 minutes (right panel). Formalin fixed cells were permeabilized with 0.1% Triton X-100 in TBS for 10 minutes at room temperature and blocked with 1% Blocker BSA (Product # 37525) for 15 minutes at room temperature. Cells were probed with a Phospho-Chk2 pThr68 polyclonal antibody (Product # PA5-17818) at a dilution of 1:100 for at least 1 hour at room temperature, washed with PBS, and incubated with DyLight 488 goat anti-rabbit IgG secondary antibody (Product # 35552) at a dilution of 1:400 for 30 minutes at room temperature. F-Actin (red) was stained with DyLight 554 Phalloidin (Product # 21834) and nuclei (blue) were stained with Hoechst 33342 dye (Product # 62249). Images were taken on a Thermo Scientific ArrayScan or ToxInsight Instrument at 20X magnification.