Detection of tumor marker CA125 in ovarian carcinoma using quantum dots.
Semiconductor quantum dots (QDs) offer several advantages over organic dyes in fluorescence-imaging applications, such as higher quantum yield, exceptional photostability, and a narrow, tunable, and symmetric emission spectrum. To explore whether QDs could specifically and effectively label tumor markers and be used in immunohistochemistry as a novel type of fluorescent probe, we used quantum dots with maximum emission wavelength 605 nm (QD605) to detect the ovarian carcinoma marker CA125 in specimens of different types (fixed cells, tissue sections, and xenograft piece). Additionally, we compared the photostability of QD signals with that of a conventional organic dye, FITC. All labeling signals of QDs were found to be more specific and brighter than those of FITC. Moreover, the QDs exhibited exceptional photostability during continuous illumination for 1 h by a high-intensity laser (Ar laser power 100 mW) at 488 nm, while the FITC signals faded very quickly and became undetectable after 24 min of illumination. These results indicate that QD-based probes can offer substantial advantages over existing fluorophores in many applications, and can be used effectively in immunohistochemistry as a novel class of fluorescent probes.
Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China.
Hui-Zhi
HZ
Wang
Hai-Yan
HY
Wang
Ru-Qiang
RQ
Liang
Kang-Cheng
KC
Ruan
D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D018613:Microscopy, Confocal / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods*; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D045663:Quantum Dots; D014018:Tissue Distribution; D015534:Trans-Activators / Q000032:analysis / Q000378:metabolism*; D035602:Transcriptional Elongation Factors
D014408:Biomarkers, Tumor; C108440:TCERG1 protein, human; D015534:Trans-Activators; D035602:Transcriptional Elongation Factors