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ISSN 1672-9145                                                 Acta Biochim Biophys Sin 2004, 36(10): 681-686                                                    CN 31-1940/Q

Detection of Tumor Marker CA125 in Ovarian Carcinoma Using Quantum Dots

Hui-Zhi WANG, Hai-Yan WANG, Ru-Qiang LIANG, and Kang-Cheng RUAN*

 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

 

Abstract        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 words         quantum dots; detection of tumor marker CA125; ovarian carcinoma

 

 

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Received: July 14, 2004        Accepted: August 15, 2004

This work was supported by the grants from the National Key Basic Research and Development Program of China (No. 2002CB713802),  the National Natural Science Foundation of China (No. 30370303), and the National High Technology Research and Development Program of China (No. 030431002)

*Corresponding author: Tel, 86-21-54921168; Fax, 86-21-54921011; E-mail, [email protected]