Development and evaluation of an enzyme-linked immunoassay for the prostate: specific antigen utilizing two monoclonal antibodies.

PSA is an important tumor-marker for prostatic cancer disease. We developed a sensitive, simple and inexpensive Sandwich ELISA for PSA with two monoclonal antibodies. The precision and reliability of the assay are reflected in the low inter- and intraassay coefficient of variation. PSA was not detectable in sera from normal females (n = 50). Sera from males with different serum levels of PSA (normal males, patients with prostate hypertrophy, prostate cancer patients, n = 79) and 15 prostate cancer patients treated with Zoladex were measured by our ELISA and by a commercially available RIA. The correlation coefficient between these both test systems was close to 1 (r = 0.97).