Skip to content


Open Access

Microbead expression arrays

  • William Wells
Genome Biology20001:spotlight-20000606-01

Published: 06 June 2000


Restriction EndonucleaseConfocal MicroscopycDNA SequenceCleavage SiteFluorescent 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