Quantum dots as fluorescent labels for detection of heat shock protein in tumor tissue using laser scanning confocal microscope

Abstract

A new Quantum Dots(Qdots) nanocrystal composed of semiconductor core and zinc sulfide shell, and its feasibility as labels in immunofluorescence analysis for the imaging of tumor biomarkers by laser scanning confocal microscope(LSCM) was investigated. Qdots taged by mercaptoacetic acid were conjugated with second antibody, then imaging differences of Heat Shock Proteins 70(HSP70) in renal carcinoma tissure sections with immunofluorescence analysis method using Qdots bioconjugates and conventional organic dye FITC were observed by LSCM to assess the brightness and opticalstability of Qdots. The experimental results showed Qdots bioconjugates achieved the better results in demonstrating HSP70 with more brighter color and more clear picture than FITC labels. Moreover, the label signals of Qdots did not fade clearly after continued exposure to a 488 nm laser for 1 h. The Qdots bioconjugates have good feasibility in immunofluorescence analysis for the bioimaging by LSCM.

Keywords

quantum dots / immunofluorescence analysis / bioimaging / laser scanning confocal microscope

References

[1] Hall M., Kazakova I., Yao Y.M. High Sensitivity Immunoassays Using Particulate Fluorescent Labels[J]. Ana. Biochem., 1999, 272(2): 165-170.

[2] Ramp U., Mahotka C., Heikaus S., . Expression of Heat Shock Protein 70 in Renal Cell Carcinoma and Its Relation to Tumor Progression and Prognosis[J]. Histology and Histopathology, 2007, 22(10): 1099-1107.

[3] Hanaki K., Momo A., Oku T., . Semiconductor quantum Dot/ Albumin Complex is a Long-life and Highly Photostable Endosome Marker[J]. Biochem. Biopgys. Res. Common., 2003, 302(2): 496-501.

[4] Zhang J., Tian B., Ge M., . Expression and Significance of Various Heat Shock Proteins in Renal Carcinoma[J]. Chinese Journal of Histochemistry and Cytochemistry, 2003, 12(3): 272-275.

[5] Pitsillides C.M., Joe E.K., Wei X., . Selective Cells Targeting with Light-absorbing Microparticles and Nanoparticles[J]. Biophy.s J., 2003, 84: 4023-4025.

[6] Gao X., Yang L., Petros J.A., . In vivo Molecular and Cellular Imaging with Quantum Dots[J]. Curr. Opi. Biotechnol., 2005, 16(1): 63-72.