Western blot analysis was performed on whole cell extracts (30 µg lysate) of U-87 MG (Lane 1), HeLa (Lane 2), HeLa treated with Staurosporine (1uM for 3 hours) (Lane 3), PANC-1 (Lane 4) and A549 (Lane 5). The blot was probed with Anti-Caspase 9 Polyclonal Antibody (Product # PA5-19904, 1:1000 dilution) and detected by chemiluminescence using Goat anti-Rabbit IgG (Heavy Chain) Superclonal™ Secondary Antibody, HRP conjugate (Product # A27036, 0.25 µg/mL, 1:4000 dilution). A 46 kDa band corresponding to Caspase 9 was observed across the cell lines tested and bands at 39 & 37 kDa was also observed corresponding to cleaved Caspase 9.