UNIT 11.11 Digital Gene Expression by Tag Sequencing on the Illumina Genome Analyzer

  1. Sorana Morrissy,
  2. Yongjun Zhao,
  3. Allen Delaney,
  4. Jennifer Asano,
  5. Noreen Dhalla,
  6. Irene Li,
  7. Helen McDonald,
  8. Pawan Pandoh,
  9. Anna-Liisa Prabhu,
  10. Angela Tam,
  11. Martin Hirst,
  12. Marco Marra

Published Online: 1 APR 2010

DOI: 10.1002/0471142905.hg1111s65

Current Protocols in Human Genetics

Current Protocols in Human Genetics

How to Cite

Morrissy, S., Zhao, Y., Delaney, A., Asano, J., Dhalla, N., Li, I., McDonald, H., Pandoh, P., Prabhu, A.-L., Tam, A., Hirst, M. and Marra, M. 2010. Digital Gene Expression by Tag Sequencing on the Illumina Genome Analyzer. Current Protocols in Human Genetics. 65:11.11:11.11.1–11.11.36.

Author Information

  1. BCCA Genome Sciences Centre, University of British Columbia, Vancouver, British Columbia, Canada

Publication History

  1. Published Online: 1 APR 2010
  2. Published Print: APR 2010


This unit provides a protocol for performing digital gene expression profiling on the Illumina Genome Analyzer sequencing platform. Tag sequencing (Tag-seq) is an implementation of the LongSAGE protocol on the Illumina sequencing platform that increases utility while reducing both the cost and time required to generate gene expression profiles. The ultra-high-throughput sequencing capability of the Illumina platform allows the cost-effective generation of libraries containing an average of 20 million tags, a 200-fold improvement over classical LongSAGE. Tag-seq has less sequence composition bias, leading to a better representation of AT-rich tag sequences, and allows a more accurate profiling of a subset of the transcriptome characterized by AT-rich genes expressed at levels below the threshold of detection of LongSAGE (Morrissy et al., 2009). Curr. Protoc. Hum. Genet. 65:11.11.1-11.11.36 © 2010 by John Wiley & Sons, Inc.


  • gene expression;
  • Tag-seq;
  • Illumina;
  • RNA;
  • cDNA;
  • tag;
  • PCR