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 μg/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.