Recognizes a protein of 52kDa, identified as prostate specific acid phosphatase (PSAP). This enzyme catalyzes the conversion of orthophosphoric monoester to alcohol and orthophosphate. It is synthesized under androgen regulation and is secreted by the epithelial cells of the prostate gland. PSAP is found in non-neoplastic adult and fetal prostatic glands, primary and metastatic prostatic carcinomas. It shows no staining in granulocytes, osteoclasts, parietal cells of the stomach, liver cells, renal cell or breast carcinomas.