Western blot was performed using Anti-IL-6 Receptor Recombinant Rabbit Monoclonal Antibody (33) (Product # MA5-29721) and a 70kDa band corresponding to full length Interleukin-6 receptor subunit alpha, and a 55kDa band corresponding to secretory Interleukin-6 receptor alpha was observed across all cell lines and tissues tested. Membrane enriched extracts (30 µg lysate) of Mouse Spleenocytes (Lane 1), RAW 264.7 (Lane 2) and RAW 264.7 conditioned medium (Lane 3) were electrophoresed using NuPAGE™ 4-12% Bis-Tris Protein 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 (1:500 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 SuperSignal™ West Dura Extended Duration Substrate (Product # 34076).