Alkor Bio, Ltd.

Prostate-specific antigen (PSA) is a single-chain glycoprotein with a molecular weight of about 32 000 Da. It is a serine protease that is produced only by human prostate epithelium. Normally PSA is secreted into seminal fluid in high concentrations, where it exhibits its enzymatic activity and is directly involved into liquefaction of seminal clot. In serum, PSA persists in low concentration. Increase of PSA concentration in serum is a sign of prostate malfunction, such as benign hyperplasia or malignant degeneration of prostate tissues. PSA level determination is widely used for the revealing and monitoring of prostate cancer patients. 

It was demonstrated that PSA makes stable complexes with different protease inhibitors. The main part of the serum PSA is a complex with α1-antichymothrypsine (PSA-ACT). But there is a great difference in free PSA/ PSA-ACT ratio in different groups of patients. In the case of benign hyperplasia the part of free PSA is higher than in the case of prostate cancer. 

OncoEIA-total PSA kit is intended for the quantitative determination of prostate-specific antigen in human serum.