UNIT 11.3 Estimation of Microbial Viability Using Flow Cytometry

  1. Hazel M. Davey1,
  2. Dieter H. Weichart1,
  3. Douglas B. Kell1,
  4. Arseny S. Kaprelyants2

Published Online: 1 MAY 2001

DOI: 10.1002/0471142956.cy1103s07

Current Protocols in Cytometry

Current Protocols in Cytometry

How to Cite

Davey, H. M., Weichart, D. H., Kell, D. B. and Kaprelyants, A. S. 2001. Estimation of Microbial Viability Using Flow Cytometry. Current Protocols in Cytometry. 11:11.3.

Author Information

  1. 1

    University of Wales, Aberystwyth, Wales, United Kingdom

  2. 2

    Russian Academy of Sciences, Moscow, Russia

Publication History

  1. Published Online: 1 MAY 2001
  2. Published Print: JAN 1999

This is not the most recent version of the article. View current version (1 SEP 2004)


For microorganisms in particular, viability is a term that is difficult to define and a state consequently difficult to measure. The traditional (and gold-standard) usage equates viability and culturability (i.e., the ability to multiply), but the process of determining culturability is often too slow. Flow cytometry provides the opportunity to make rapid and quantitative measurements of dye uptake in large numbers of cells, and we can therefore exploit the flow cytometric approach to evaluate so-called viability stains and to develop protocols for more routine assessments of microbial viability. This unit is primarily commentary, but several basic protocols have been included to ensure that users have a firm basis for attempting these reasonably difficult assays on traditional flow cytometer instruments. What is clear is that each assay must be carefully validated with the particular microorganism of interest before being applied in any research, clinical, or service form.