A comparative study of the use of monoclonal antibodies using three different immunohistochemical methods: an evaluation of monoclonal and polyclonal antibodies against human prostatic acid phosphatase.

The use of immunohistochemical methods has been advocated for the detection and localization of prostatic acid phosphatase in paraffin sections of human prostate. This article explores the possible advantages of utilizing monoclonal antibodies in this method. Monoclonal antibodies, specific for human prostatic acid phosphatase, were integrated into three different immunohistochemical procedures. In the first method, a three-layer peroxidase-antiperoxidase (PAP) system was employed; the monoclonal antibody was followed by rabbit bridge antibody directed against mouse immunoglobulin and mouse PAP complex. The second method was a three-layer system utilizing biotin-labeled horse anti-mouse antibody as "bridge" antiserum between the primary monoclonal antibody and an avidin-biotin-horseradish peroxidase complex. The third method was a four-layer system; the monoclonal antibody was followed by rabbit anti-mouse serum, swine anti-rabbit immunoglobulin as the bridge antibody and rabbit PAP complex. It was found that some, but not all, monoclonal antibodies can be used for the detection of prostatic acid phosphatase in paraffin sections. The four-layer PAP method was found to be the most sensitive method of the three systems tested; however, the avidin-biotin method required the least amount of time. No significant difference in the quality of staining was observed between monoclonal antibodies and carefully absorbed conventional antiserum.