Western blot analysis was performed on modified whole cell extracts (1% SDS) (30 µg lysate) of HeLa (Lane 1), MCF7 (Lane 2), A-431 (Lane 3), K-562 (Lane 4), Hep G2 (Lane 5), HCT 116 (Lane 6), Panc-1 (Lane 7), U-2 OS (Lane 8) and COS-7 (Lane 9). The blot was probed with Anti- PCNA Polyclonal Antibody (Product # MA5-17166, 1:500 dilution) and detected by chemiluminescence using Goat anti-Mouse IgG (H+L) Superclonal™ Secondary Antibody, HRP conjugate (Product # A28177, 0.25µg/mL, 1:4000 dilution). A 70 kDa band corresponding to RPA70 was observed across the cell lines tested.