Cellular imaging and surface marker labeling of hematopoietic cells using quantum dot bioconjugates.

Semiconductor quantum dots (qdots) are emerging as a new class of fluorescent labels. The unique optical properties of qdots make them appealing in laboratory diagnosis; however, qdot-based probes remain to be developed and evaluated for clinical laboratory applications. In this study, 2 different approaches were employed to label hematopoietic cells with qdots. The first was based on a generalized intracellular delivery of qdots using qdot-transferrin conjugates through receptor-mediated endocytosis. Hematopoietic cells from umbilical cord blood or bone marrow were successfully labeled with qdot-transferrin in cell cultures. The fluorescence signal of qdot-transferrin was detected in the cytoplasmic location. The second approach was to use qdot-antibodies for labeling cell surface markers. The monoclonal antibodies to CD5, CD19, and CD45 surface antigens were conjugated to qdots with distinct emission spectra. The qdot-linked antibodies were shown to bind successfully to specific cell markers on lymphocytes. The signal obtained from the labeling of cells was detectable by using fluorescence microscopy and flow cytometry. The qdot signals were shown to be target specific, bright, and photo stable. The results of this study demonstrated the feasibility of using qdots for cell labeling and surface marker analysis of hematopoietic cells. Given the superior optical properties of qdots as compared to conventional fluorescence dyes, the qdot-based probe offers a promising tool for hematology analysis in clinical laboratories.

[1]  M. Bruchez,et al.  Immunofluorescent labeling of cancer marker Her2 and other cellular targets with semiconductor quantum dots , 2003, Nature Biotechnology.

[2]  Vincent Noireaux,et al.  In Vivo Imaging of Quantum Dots Encapsulated in Phospholipid Micelles , 2002, Science.

[3]  H. Mattoussi,et al.  Conjugation of luminescent quantum dots with antibodies using an engineered adaptor protein to provide new reagents for fluoroimmunoassays. , 2002, Analytical chemistry.

[4]  A. Henglein,et al.  Small-particle research: physicochemical properties of extremely small colloidal metal and semiconductor particles , 1989 .

[5]  J. Matthew Mauro,et al.  Long-term multiple color imaging of live cells using quantum dot bioconjugates , 2003, Nature Biotechnology.

[6]  S. Nie,et al.  In vivo cancer targeting and imaging with semiconductor quantum dots , 2004, Nature Biotechnology.

[7]  J. Matthew Mauro,et al.  Self-Assembly of CdSe−ZnS Quantum Dot Bioconjugates Using an Engineered Recombinant Protein , 2000 .

[8]  P. Guyot-Sionnest,et al.  Synthesis and Characterization of Strongly Luminescing ZnS-Capped CdSe Nanocrystals , 1996 .

[9]  Hans C. Fischer,et al.  Design and characterization of lysine cross-linked mercapto-acid biocompatible quantum dots , 2006 .

[10]  A. Alivisatos.  Semiconductor Clusters, Nanocrystals, and Quantum Dots , 1996, Science.

[11]  M. Bawendi,et al.  (CdSe)ZnS Core-Shell Quantum Dots - Synthesis and Characterization of a Size Series of Highly Luminescent Nanocrystallites , 1997 .

[12]  S. Nie,et al.  Quantum dot bioconjugates for ultrasensitive nonisotopic detection. , 1998, Science.

[13]  J. Post,et al.  Quantum dot ligands provide new insights into erbB/HER receptor–mediated signal transduction , 2004, Nature Biotechnology.

[14]  W. Webb,et al.  Water-Soluble Quantum Dots for Multiphoton Fluorescence Imaging in Vivo , 2003, Science.

[15]  Sangeeta N. Bhatia,et al.  Intracellular Delivery of Quantum Dots for Live Cell Labeling and Organelle Tracking , 2004 .

[16]  D. Balding,et al.  HLA Sequence Polymorphism and the Origin of Humans , 2006 .