The prostate specific antigen (PSA) is an intracellular glycoprotein only synthesized by the male prostate gland and in seminal plasma. This protein is now used by the forensic medicine as a choice marker to detect sexual assaults, even when they are committed by men who had vasectomy.

Bluestar Identi-PSA Semen Detection Test is a rapid qualitative assay for PSA detection from traditional biological samples (serum, plasma, or blood), but also from sperm samples collected with a swab either on the clothes or on the victims’ bodies.

The method employs a unique combination of monoclonal dye conjugate (mouse) and monoclonal antibodies (solid phase) to selectively identify PSA antigen in the samples, with a high degree of sensitivity.

As the test sample flows through the absorbent paper, the labelled antibody-dye conjugate binds to the antigen, thus forming an antigen-antibody complex. This complex binds to the anti-PSA antibodies in the positive reaction zone and produces a colored line if the PSA antigen level is higher than 4 ng/ml. If there is no antigen, no line appears in the test zone.

The reaction mixture continues flowing through the absorbent paper, past the test zone and the control zone . Unbound conjugate binds to the reagents in the control zone, producing a colored line indicating that the reagents are functioning correctly.