Protein A ELISA Kit | F050

Protein A ELISA Kit is intended for use in quantitating Protein A ligands from natural (Staphylococcus aureus) and structurally conserved E.coli recombinant expressed constructs. The kit is for Research and Manufacturing Use Only and is not intended for diagnostic use in humans or animals. Cygnus manufactures two other Protein A detection kits, Cat #s F050H and F400. Cat # F050H is preferred over F050 when the product antibody is human or otherwise shows interference in the detection of Protein A. Our newest Protein A kit Cat # F400 incorporates some improvements over the two earlier kits and is designed to better detect the newer, unnatural constructs of Protein A such as the MabSelect SuReTM ligand sold by GE Healthcare. The Protein A assay is a two-site immunoenzymetric assay. Samples containing Protein A are reacted in microtiter strips coated with a polyclonal anti-Protein A capture antibody. A second biotinylated Monoclonal antiProtein A antibody is reacted forming a sandwich complex of solid phase antibody-Protein A-biotinylated antibody. After a wash step to remove any unbound reactants, the strips are then reacted with Streptavidin labeled with Alkaline Phosphatase enzyme which will bind to any of the biotinylated antibody bound to the strip. After another wash step to remove unbound Streptavidin: alkaline phosphatase, the plates are then reacted with p-nitrophenyl phosphate (PNPP) substrate. The amount of hydrolyzed substrate is read on a microtiter plate reader and is directly proportional to the concentration of Protein A present. Accurate quantitation is achieved by comparing the signal of unknowns to Protein A standards assayed at the same time.