Measurement of Immunoperoxidase Activity. A Rapid and Reproducible Immunoassay for Quantitation of Cellular Antigens

A procedure is described making it possible to obtain quantitative data with the immunohistochemical peroxidase anti--peroxidase (PAP) technique. After applying PAP on fixed fibroblast preparations, peroxidase enzymic activity is measured on solubilized immune-complexes. The results show this technique to be sensitive and reproducible. Differences in the amounts of the same antigen (alpha2-macroglobulin) are detected in differently treated fibroblast preparations. The value of the technique for the demonstration of cellular antigens is discussed.