Anti-RFP Antibody - Western Blot. Western blot of RFP recombinant protein detected with polyclonal anti-RFP antibody. Lane 1 shows no reaction against a GFP recombinant protein present in 10 ug of HeLa cell extract. Lane 2 shows a single band detected in 10 ug of a HeLa lysate containing RFP recombinant protein as a 27 kD band. A 4-12% Bis-Tris gradient gel (Invitrogen) was used for SDS-PAGE. The membrane was blocked and then probed with Anti-RFP diluted 1:2500 for 1 h at RT followed by washes and reaction with a 1:5000 dilution of IRDye800 conjugated Goat-a-Rabbit IgG [H&L] MX (. IRDye800 fluorescence image was captured using the Odyssey Infrared Imaging System developed by LI-COR. IRDye is a trademark of LI-COR, Inc. Other detection systems will yield similar results.