| pubmed-article:10405822 | pubmed:abstractText | Chelates with fluorescent lanthanides such as europium and terbium are widely used in immunofluorometric assays, e.g. for the measurement of different molecular forms of prostate-specific antigen (PSA) in serum for detection and monitoring of prostate cancer. These chelates have also been introduced as non-radioactive labels in immunocytochemistry and in situ hybridization. In the present study, sections of non-malignant prostate were investigated using monoclonal IgGs against PSA. Detection of specific immunostaining employing time-resolved fluorescence with europium-labeled streptavidin was compared with conventional detection by streptavidin conjugated to horse-radish peroxidase. The high PSA concentration in the tissue produced high intensity, specific time-resolved fluorescence signals in the epithelial cells of the prostate gland without disturbance from non-specific tissue autofluorescense. This allowed short exposure times to be used which resulted in insignificant photobleaching. Two of the three europium-chelates evaluated yielded high signal intensities. Counterstaining was found to be optimal with Gill No. 1-Haematoxylin solution and Merckoglas was the best mounting medium for the europium chelates tested. In conclusion, time-resolved fluorescence imaging is an attractive alternative to conventional detection of streptavidin conjugated to horse-radish peroxidase, as it provides linear, high intensity, specific signals subsequent to the decay of non-specific tissue autofluorescence. | lld:pubmed |
