title: Immunofluorescent labeling of cancer marker Her2 and other cellular targets with semiconductor quantum dots.
abstract: Semiconductor quantum dots (QDs) are among the most promising emerging fluorescent labels for cellular imaging. However, it is unclear whether QDs, which are nanoparticles rather than small molecules, can specifically and effectively label molecular targets at a subcellular level. Here we have used QDs linked to immunoglobulin G (IgG) and streptavidin to label the breast cancer marker Her2 on the surface of fixed and live cancer cells, to stain actin and microtubule fibers in the cytoplasm, and to detect nuclear antigens inside the nucleus. All labeling signals are specific for the intended targets and are brighter and considerably more photostable than comparable organic dyes. Using QDs with different emission spectra conjugated to IgG and streptavidin, we simultaneously detected two cellular targets with one excitation wavelength. The results indicate that QD-based probes can be very effective in cellular imaging and offer substantial advantages over organic dyes in multiplex target detection.
authors.affiliation: Quantum Dot Corporation, 26118 Research Rd., Hayward, CA 94545, USA. xwu@qdots.com
authors.forename: Xingyong
authors.initials: X
authors.lastname: Wu
authors.forename: Hongjian
authors.initials: H
authors.lastname: Liu
authors.forename: Jianquan
authors.initials: J
authors.lastname: Liu
authors.forename: Kari N
authors.initials: KN
authors.lastname: Haley
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Treadway
authors.forename: J Peter
authors.initials: JP
authors.lastname: Larson
authors.forename: Nianfeng
authors.initials: N
authors.lastname: Ge
authors.forename: Frank
authors.initials: F
authors.lastname: Peale
authors.forename: Marcel P
authors.initials: MP
authors.lastname: Bruchez
mesh_terms: D016475:3T3 Cells / Q000378:metabolism / Q000473:pathology; D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D003460:Crystallization / Q000379:methods; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods; D004563:Electrochemistry; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D005455:Fluorescent Antibody Technique / Q000379:methods; D005456:Fluorescent Dyes; D006801:Humans; D051379:Mice; D008832:Microchemistry / Q000379:methods; D008863:Microspheres; D036103:Nanotechnology / Q000379:methods*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000378:metabolism*; D012666:Semiconductors; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods*; D013194:Staining and Labeling / Q000295:instrumentation / Q000379:methods*; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D005456:Fluorescent Dyes; D018719:Erb-b2 Receptor Tyrosine Kinases