Hybritech Total and Free Prostate-specific Antigen Assays Developed for the Beckman Coulter Access Automated Chemiluminescent Immunoassay System: A Multicenter Evaluation of Analytical Performance

Abstract
Previously reported clinical trials have shown that measurement of the different forms of prostate-specific antigen (PSA) (1) is useful in the differentiation of prostate cancer from benign prostatic conditions. Men with prostate cancer tend to have lower percent free PSA (%FPSA) values than men with benign disease (2)(3)(4); %FPSA is the ratio of free PSA to total PSA times 100%.