Comparison of quantum-dots- and fluoresceinisothiocyanate- based technology for detecting prostate-specific antigen expression in human prostate cancer

Quantum dots (QDs) are a new class of fluorescent labelling for biological and biomedical applications. In this study, the authors evaluated the sensitivity and stability of quantum-dots-based immunolabelling, in comparison with the conventional fluorescein-isothiocyanate-based immunolabelling (FITC), for detecting prostate-specific antigen (PSA) expression in human prostate cancer. The authors´ data revealed that the two methods had similar sensitivity in differential display of the PSA expression correlated with tumour stage and grade (K = 0.88, p<; 0.001). Moreover, the intensity of QDs fluorescence remain stable for 10 days after conjugation to the PSA protein in 97<; of the cases and more than 1 month in 92% of the cases, although the FITC fluorescence became undetectable after 6<;min for all cases.