Prostate specific acid phosphatase (PSAP) is an enzyme that 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.

The PSAP antibody (with azide) can be stored at 2-8°C. The azide-free format should be aliquoted and stored at -20°C or colder.