Quantum-dot-tagged microbeads for multiplexed optical coding of biomolecules

• Published in: Nature biotechnology Vol. 19; no. 7; pp. 631 - 635
• Main Authors: Nie, Shuming, Han, Mingyong, Gao, Xiaohu, Su, Jack Z
• Format: Journal Article
• Language: English
• Published: New York, NY Nature 01.07.2001; Nature Publishing Group
• Subjects: Biological and medical sciences; biomolecules; Biotechnology; Biotechnology - methods; Cadmium; Cadmium selenide; Deoxyribonucleic acid; DNA; DNA - metabolism; Emissions; Fluorescent Dyes; fluorophores; Fundamental and applied biological sciences. Psychology; Gene expression; Genetic Techniques; high-throughput screening; Hybridization; Medical research; Methods. Procedures. Technologies; microbeads; Microelectromechanical systems; Microscopy, Fluorescence - methods; Nanocrystals; Nucleic Acid Hybridization - methods; Nucleic acids; Oligonucleotide Array Sequence Analysis - methods; Oligonucleotides - chemistry; Optical properties; Others; Polymers; Publishing; Quantum dots; Spectrometry, Fluorescence - methods; Sulfides; Various methods and equipments; Multiplexing; Molecular hybridization; Quantum dot; Semiconductor materials; Fluorophore; Coding; Technology; DNA; Optical properties; Polymer; Application
• ISSN: 1087-0156; 1546-1696
• DOI: 10.1038/90228

Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots (zinc sulfide-capped cadmium selenide nanocrystals) into polymeric microbeads at precisely controlled ratios. Their novel optical properties (e.g., size-tunable emission and simultaneous excitation) render these highly luminescent quantum dots (QDs) ideal fluorophores for wavelength-and-intensity multiplexing. The use of 10 intensity levels and 6 colors could theoretically code one million nucleic acid or protein sequences. Imaging and spectroscopic measurements indicate that the QD-tagged beads are highly uniform and reproducible, yielding bead identification accuracies as high as 99.99% under favorable conditions. DNA hybridization studies demonstrate that the coding and target signals can be simultaneously read at the single-bead level. This spectral coding technology is expected to open new opportunities in gene expression studies, high-throughput screening, and medical diagnostics.