Western blot was performed using Anti-MLH-1 Rabbit Polyclonal Antibody (Product # PA5-79675) and a 84 kDa band corresponding to MLH-1 was observed in cell lines tested except HCT 116 and DU 145 which are reported to be negative. Modified whole cell extracts (1% SDS) (30 µg lysate) of HeLa (Lane 1), A-431 (Lane 2), SW480 (Lane 3), HCT 116 (Lane 4), PC3 (Lane 5), DU 145 (Lane 6) and Raji (Lane 7) were electrophoresed using Novex® NuPAGE® 4-12% Bis-Tris Protein Gel (Product # NP0322BOX). Resolved proteins were then transferred onto a nitrocellulose membrane (Product # IB23001) by iBlot® 2 Dry Blotting System (Product # IB21001). The blot was probed with the primary antibody (0.5 µg/ml) and detected by chemiluminescence with Goat anti-Rabbit IgG (H+L) Superclonal™ Recombinant Secondary Antibody, HRP (Product # A27036, 1:4000 dilution) using the iBright FL 1000 (Product # A32752). Chemiluminescent detection was performed using Novex® ECL Chemiluminescent Substrate Reagent Kit (Product # WP20005). An uncharacterized band (*) was observed in SW480 and Raji around ~32 kDa.