Anti-V5 Epitope Tag Polyclonal Antibody - Western Blot. Anti-V5 epitope tag polyclonal antibody detects V5-tagged recombinant protein by western blot. This antibody was used at 1.0 ug/ml to detect 0.05 ug (lane 2) of full-length recombinant mouse serum albumin containing the V5 epitope tag at the carboxy end. Comparison to MW markers (lane 1) indicates detection of monomeric V5 tagged albumin. A 4-20% gradient gel was used to separate the protein by SDS-PAGE under non-reducing conditions. The protein was transferred to nitrocellulose using standard methods. After blocking the membrane was probed with the primary antibody overnight at 4C followed by washes and reaction with a 1:10000 dilution of IRDye 800 conjugated Gt-a-Rabbit IgG [H&L] (code for 45 min at room temperature. LICORs Odyssey Infrared Imaging System was used to scan and process the image. Other detection systems will yield similar results.