Biotinylated anti-polyhistidine antibody is offered for use in Western blot detection of fusion proteins tagged with 6× histidine. The antibody is raised in goat against a synthetic 6× His peptide, affinity purified and optimally labeled with biotin. Binding of this antibody is equivalent whether the polyhistidine tag is on the N- or C-terminus of the recombinant protein. This biotinylated anti-polyhistidine antibody has been optimized for use with the VECTASTAIN ABC AmP Kit, an amplified alkaline phosphatase-based detection system with chromogenic or chemiluminescent/fluorescent options, but can be used with any avidin or streptavidin based detection method. Packaged as a 0.25 mg unit, the product can be used at a 1:1000 dilution yielding 250 mls of working solution.