Point-of-care fluorescence immunoassay for prostate specific antigen

Background: Prostate specific antigen (PSA) is widely used as a clinical marker for diagnosis, screening, and prognosis of prostate cancer. A fluorescence (FL) dye-incorporated immunochromatographic assay (ICA) was developed for detection of PSA concentration in whole blood or serum. Methods: Whole blood or serum mixed with FL-conjugated detector was loaded onto a cartridge and incubated for 12 min. The FL intensity of the cartridge was then measured in a laser FL scanner. The analytical performance of the FL-ICA system was evaluated by precision and recovery tests. The comparability of the new method was examined with an automated analyzer. Results: A reliable correlation between area ratio (A(T)/A(C)), reflecting FL intensity of test/control line, and PSA concentration was observed (r = 0.998). The CVs of intra- and inter-assay precision in a range of 2.5-8 mu g/l were <6.0% and 4.5%, respectively, and analytical recovery of the FL-ICA system fell within 6.5% at the tested samples. When the FL-ICA method was compared with Abbott AxSYM and Bayer Centaur analyzers, there were strong correlations (r = 0.993 and r = 0.992, p < 0.0001). Conclusion: The FL-ICA system with point-of-care-testing (POCT) appeared to be an easy, fast and suitable method for measurement of PSA concentration in whole blood, and needs no accessory equipment to separate serum. (C) 2009 Elsevier B.V. All rights reserved.