Detection of the cancer marker CD146 expression in melanoma cells with semiconductor quantum dot label.

The use of highly specific and highly sensitive quantum dots immunofluorescent label is a promising approach for biomedical imaging in cancer cells. Human melanoma cell adhesion molecule CD146, overexpressed on the surface of melanoma cells, is an important target for melanoma diagnostics. We synthesized PEG-COOH capped highly fluorescent CdSe/ZnS QDs and conjugated them with streptavidin to prepare QD-SA label. Then, we used QD-SA to link with biotinylated goat anti-mouse IgG and mouse anti-human CD146 to label CD146 overexpressed on live and fixed cells by FACS and Confocal microscopy. Labeling of target cells was shown to have high brightness, photostability, and specificity. Advantages of QD conjugates over FITC conjugates are discussed. The results indicate that construction based on QD-SA label, biotinylated IgG and CD146 antibody can be successfully used for detection of melanoma cells for biomedical applications.