Optically encoded microspheres for high-throughput analysis of genes and proteins

Xiaohu Gao, Minyong Han, Shuming Nie

Research output: Contribution to journalConference articlepeer-review


We have developed a novel optical coding technology for massively parallel and high-throughput analysis of biological molecules. Its unprecedented multiplexing capability is based on the unique optical properties of semiconductor quantum dots (QDs) and the ability to incorporate multicolor QDs into small polymer beads at precisely controlled ratios. The use of 10 intensity levels and 6 colors could theoretically code one million nucleic acid or protein sequences. Imaging and spectroscopic studies 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 results 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 diagnosis.

Original languageEnglish (US)
Pages (from-to)210-217
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 2002
Externally publishedYes
EventBiomedical Nanotechnology Architectures and Applications - San Jose, CA, United States
Duration: Jan 20 2002Jan 24 2002


  • Biomedical diagnostics
  • Drug screening
  • Genomics
  • High-throughput
  • Multiplexing
  • Nanocrystals
  • Proteomics
  • Quantum dots
  • Spectral barcoding

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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