Document Type: Original Article
Department of Radioisotope, Nuclear Research Center, AOEI, Tehran, Iran
Introduction: Prostate specific antigen (PSA) is one of the most sensitive markers for diagnosis of prostate cancer. Immunoradiometric kit (IRMA) is a common and sensitive method for determination of PSA in clinical laboratories. This kit has four major components: solid phase coated with monocolonal antibody, pair antibody labelled with I-125, series of standards in different ranges of concentration and lyophilized control samples. In IRMA method, PSA is determined in human serum. Therefore, matrix of standards have to be similar to human serum. Using human serum as standard has many shortcomings namely biohazard contamination, instability, serum protein precipitation and unavailability. Artificial matrix however, is an ideal substitute for human serum. Methods: In this study, we used an artificial matrix as standard sample and evaluated its effects including reproducibility, sensitivity, precision and stability for determination of PSA in comparision to human serum. Results: The specificity, sensitivity, storage condition and the stability of these standards prepared with artificial matrix were studied. Similar results in comparison to human serum was observed. Conclusion: The prepared standards with this matrix had suitable and ideal properties and it can be used as standard in PSA assay kit.