Western Blot was performed using Anti-GFP Polyclonal Antibody, Alexa Fluor 488 (Product # A-21311) by loading whole cell extracts of untransfected and transiently transfected HEK-293E lysates: untransfected, 40 µg (Lane 1), empty vector control, 40 µg (Lane 2), p65-GFP, 40 µg (Lane 3), His-p65-YFP, 40 µg (Lane 4), H3-mCherry, 40 µg (Lane 5) and 25 ng Positope (Lane 6) 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). A ~92 kDa band of p65-GFP were observed in transfected lysates on probing with primary antibody (1:2000 dilution) and and detected by chemiluminescence with Goat anti-Rabbit IgG (H+L) Superclonal™ Secondary Antibody, HRP (Product # A27036, 1:4000 dilution) using the iBright FL 1500 (Product # A44241). Chemiluminescent detection was performed using Novex® ECL Chemiluminescent Substrate Reagent Kit (Product # WP20005). Positope (Product # R90050) is a 53 kDa recombinant protein consisting multiple epitope tags, which has been used as a positive control for GFP detection. This product also detects Yellow Fluorescent Protein (YFP), a variant of GFP as observed in Lane 4. No cross-reactivity was seen with mCherry (RFP family) expressing lysate.