Description
Introduction: Prostate specific antigen (PSA) is a 34 kD glycoprotein produced by the cells of the prostate gland. PSA occurs in different molecular forms in serum: free PSA (fPSA) and complexed PSA (cPSA), the sum of which corresponds to total PSA (tPSA). PSA is present in small quantities in the serum of normal men, and is often elevated in the presence of prostate cancer and in other prostate disorders. A blood test to measure PSA is considered the most effective test currently available for the early detection of prostate cancer, but this effectiveness has also been questioned. Rising levels of PSA over time are associated with both localized and metastatic prostate cancer (CaP).
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to PSA. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific for PSA and 3 Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB (3,3',5,5' tetramethyl-benzidine) substrate solution is added to each well. Only those wells that contain PSA, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm +/- 2 nm. The concentration of PSA in the samples is then determined by comparing the O.D. of the samples to the standard curve