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Microbead expression arrays

Genome Biology20001:spotlight-20000606-01

  • Published:


  • Restriction Endonuclease
  • Confocal Microscopy
  • cDNA Sequence
  • Cleavage Site
  • Fluorescent Probe

Strategies for expression analysis range from exhaustive sequencing (and thus counting) of cDNAs to hybridization arrays. In the June issue of Nature Biotechnology Brenner et al. describe a method that combines the digital precision of the former with the speed and throughput of the latter (Nat. Biotech. 2000, 18:630-634). Brenner et al. attach tagged cDNAs to microbeads and then sequence the overhanging ends of the cDNAs by detecting the hybridization of fluorescently labeled probes. After one overhang is identified, a binding site for a type IIs restriction endonuclease (within the probe) is used to cleave a distant cleavage site (within the cDNA sequence) to expose a new overhang. The coming and going of fluorescent probes is monitored by confocal microscopy of the microbeads, which are immobilized in a flow cell. Hundreds of thousands of mRNAs are identified in a few days, exceeding the throughput per machine of conventional sequencers by over 10-fold.


  1. Serial analysis of gene expression.Google Scholar
  2. Quantitative monitoring of gene expression patterns with a complementary DNA microarray.Google Scholar
  3. Nature Biotechnology, []


© BioMed Central Ltd 2000