Abstract: A kit containing the reagents necessary for the qualitative or quantitative demonstration of epidermal growth factor receptor (EGFR) in formalin-fixed, paraffin-embedded tissue sections. A immunohistochemical staining procedure is employed which utilizes a primary monoclonal mouse antibody that selectively binds to EGFR. The primary antibodies bound to tissue antigens are detected using a peroxidase labeled polymer that is conjugated with secondary anti-mouse immunoglobulin antibodies. The enzymatic conversion of the subsequently applied chromogen results in formation of a visible reaction product at the site of the EGFR antigen. Following development of the chromogen, specimens may then be counterstained and coverslipped. Results are interpreted using a light microscope or other optical imaging device. The detection system is adapted for both manual and automated staining.

Abstract: The preparation and use of stable, ready-to-use substrate-chromogen solutions for the detection and quantification of peroxidase or pseudoperoxidase activity are described. The substrate-chromogen solution according to the present invention contains a buffer, preferably imidazole buffer, a polymer, a hydroperoxide substrate, a chromogenic organic electron donor and electron donor of the carbohydrate type as a stabilizer. The substrate-chromogen solution retains its full peroxidatic activity and develops a negligible color during storage.