Western blot was performed using Anti-CX3CR1 Polyclonal Antibody (Product # PA1-28839) and a 56 kDa band corresponding to CX3CR1 was observed in Mouse Brain and Rat Brain but not in Mouse Spleen which is reported to be negative. Tissue extracts (30 µg lysate) of Mouse Brain (Lane 1), Rat Brain (Lane 2) and Mouse Spleen (Lane 3) were electrophoresed using 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 (1:1000 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). (Note: Uncharacterized bands (*) were observed in Mouse Brain and Rat Brain tissue lysates).