Quantum dots coupled streptavidin and its application in lipid rafts protein characterization

Bioconjugated quantum dots (QDs) are widely used in optics, materials, bioluminescent probes and clinical testing due to their unique spectroscopic properties. Particularly, one of the most significant and clinically relevant applications is the use of multicolor QDs probes in immunohistochemistry. Herein, we prepared Cadmium telluride (CdTe) quantum dots using aqueous phase synthesis before characterization with ultraviolet (UV) and infra-red (IR) spectroscopy. The purified QDs were conjugated with streptavidin (SA) before their characterization via agarose gel electrophoresis. Afterwards, we conjugated biotin-streptavidin with lipoproteins and characterized the resultant lipid raft proteins with immunofluorescence. The proteins in the lipid rafts exhibited strong fluorescence due to the binding of the QDs to SA coupled with the specificity and amplification of the biotin-SA system (BSAS). Therefore, CdTe QDs-SA with strong fluorescence intensity and good optical stability were obtained via aqueous phase synthesis, amid successful characterization of the lipid rafts with immunofluorescence using multicolored QDs-SA conjugates. Thus, different fluorescence colors (QDs-SA) can be used to characterize different proteins on lipid rafts. This work provides an idea for biological protein staining to play a better role in immunohistochemistry.