UNIT 12.6 Quantitative Fluorescence In Situ Hybridization (QFISH) of Telomere Lengths in Tissue and Cells

  1. Jacintha N. O'Sullivan1,
  2. Jennifer C. Finley2,
  3. Rosa-ana Risques2,
  4. Wen-Tang Shen2,
  5. Katherine A. Gollahon2,
  6. Peter S. Rabinovitch2

Published Online: 1 AUG 2005

DOI: 10.1002/0471142956.cy1206s33

Current Protocols in Cytometry

Current Protocols in Cytometry

How to Cite

O'Sullivan, J. N., Finley, J. C., Risques, R.-a., Shen, W.-T., Gollahon, K. A. and Rabinovitch, P. S. 2005. Quantitative Fluorescence In Situ Hybridization (QFISH) of Telomere Lengths in Tissue and Cells. Current Protocols in Cytometry. 33:12.6:12.6.1–12.6.15.

Author Information

  1. 1

    St Vincent's University Hospital, Elm Park, Dublin, Ireland

  2. 2

    University of Washington, Seattle, Washington

Publication History

  1. Published Online: 1 AUG 2005
  2. Published Print: JUL 2005


Telomeres are repetitive DNA sequences at the end of each chromosome that provide stability and prevent end-to-end chromosome fusions. In order to understand mechanisms responsible for telomere shortening, it is necessary to develop methods for accurate telomere length measurement that can be applied to archival and fresh tissue and cells. This unit describes in situ–based quantitative fluorescence in situ hybridization (QFISH) protocols using a fluorescence-conjugated telomere probe (peptide nucleic acid, PNA) that stains telomeres proportionally to their length. These protocols can be used on formalin-fixed paraffin-embedded tissue, lightly fixed tissue, cells isolated from tissue, cultured cells, and agar-embedded cells. The basic protocol for QFISH staining is modified to achieve excellent QFISH staining for a variety of cell preparations. Image-analysis techniques to quantitate average telomere lengths from tissues and isolated stained cells are also described.


  • telomere length;
  • quantitative fluorescence in situ hybridization (QFISH);
  • tissue sections;
  • cultured cells;
  • fixation protocols