CdTe量子点对HeLa细胞的初步标记

Labeling HeLa Cells with CdTe Quantum Dots

采用巯基丙酸作为稳定剂在水相中合成了水溶性的CdTe量子点,并通过量子点外层包被的羧基实现了量子点与兔抗人癌胚抗原抗体和山羊抗兔免疫球蛋白的链接.把链接了兔抗人癌胚抗原抗体的量子点溶液和链接山羊抗兔免疫球蛋白的量子点溶液作为荧光探针,利用直接法和间接法分别对HeLa活细胞和固定细胞进行了标记.通过荧光显微镜成像观察到直接法和间接法均可以对HeLa细胞进行标记,但间接法具有更好的特异性,表明可以通过癌细胞表面的癌胚抗原与抗体之间的免疫反应实现对癌细胞的荧光标记.

Mercaptopropionic acid was taken as stabilizer to synthesize water-soluble （kiTe quantum dots, and the dots were covalently linked to the anti-CEA8 （carcinoembryonic antigen） antibody for rabbit and anti-rabbit immunoglobulin for goat by the carboxyl functional groups covered by outer layer of CdTe QDs. The conjugation has obvious effect on the optical properties of CdTe QDs, and the conjugation enhances fluorescence intensity in the presence of anti-CEA8 for rabbit and anti-rabbit immunoglobulin for goat with the blue-shift of their maximum emission peaks, which are proved more stable than that of bare CdTe QDs. Both the QDs-antibody and QDs-immunoglobulin are used as bio-labels to directly and indirectly label live or fixed HeLa cells. Through fluorescence microscopy, it is observed that HeLa cells can be labeled through both direct and indirect methods, but the latter has better specificity. All these results demonstrate that cancer cells can be successfully stained through immunoreactions between antigen and antibody.