Western blot was performed using Anti-TdT Recombinant Rabbit Monoclonal Antibody (RM379) (Product # MA5-33040) and a 58 kDa band corresponding to DNA nucleotidylexotransferase was observed across positive cell lines (Molt-4, Jurkat and Reh); and not across negative cell lines A-431,Raji, Ramos, HeLa and Daudi). Whole cell extracts (30 µg lysate) of MOLT-4 (Lane 1), A-431 (Lane 2), Jurkat (Lane 3), Raji (Lane 4), Ramos (Lane 5), Reh (Lane 6), HeLa (Lane 7) and Daudi (Lane 8) were electrophoresed using NuPAGE™ 10% Bis-Tris Protein Gel (Product # NP0301BOX). 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 (1:1500 dilution) and detected by chemiluminescence with Goat anti-Rabbit IgG (Heavy Chain) 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).