Western blot was performed using Anti-CtIP Polyclonal Antibody, (Product # PA5-21983) and a 110 kDa band corresponding to CtIP was observed in the cell lines tested. Modified whole cell extracts (1%SDS) (30 µg lysate) of T-47D (Lane 1), MCF7 (Lane 2), MDA-MB-231 (Lane 3), SK-BR-3 (Lane 4) and MCF 10A (Lane 5) were electrophoresed using Novex® NuPAGE® 4-12 % Bis-Tris gel (Product # NP0321BOX). 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 (1:2000 dilution) and detected by chemiluminescence with Goat anti-Rabbit IgG (Heavy Chain), Superclonal™ Recombinant Secondary Antibody, HRP conjugate (Product # A27036, 1:4000 dilution) using the iBright FL 1000 (Product # A32752). Chemiluminescent detection was performed using SuperSignal™ West Dura Extended Duration Substrate (Product # 34076).