UNIT 11.17 Labeling of Bacterial Pathogens for Flow Cytometric Detection and Enumeration

  1. Kristi R. Harkins,
  2. Kelley Harrigan

Published Online: 1 SEP 2004

DOI: 10.1002/0471142956.cy1117s29

Current Protocols in Cytometry

Current Protocols in Cytometry

How to Cite

Harkins, K. R. and Harrigan, K. 2004. Labeling of Bacterial Pathogens for Flow Cytometric Detection and Enumeration. Current Protocols in Cytometry. 29:11.17:11.17.1–11.17.20.

Author Information

  1. Advanced Analytical Technologies, Inc., Ames, Iowa

Publication History

  1. Published Online: 1 SEP 2004
  2. Published Print: JUL 2004


Traditional uses of flow cytometry have been for research and diagnostic purposes, on mammalian cells. This unit focuses on using a flow cytometer for enumerating specific bacteria and parasites. Several different labeling methods are discussed, as well as how to set up a cytometer for detecting and enumerating bacteria. Labeling methods include direct detection with a primary fluorochrome-conjugated antibody and indirect labeling with an unconjugated primary and a fluorochrome-conjugated secondary antibody, as well as labeling with rRNA sequence-specific peptide nucleic-acid probes end-labeled with a fluorochrome. Data and methods throughout this unit focus on detection of Salmonella in clean matrices; however, pertinent information is also provided on using these methods to label other pathogens. The Commentary covers critical aspects of the protocols, and also includes information and suggestions on the application of these methods for testing in the food and pharmaceutical industries, as well as in environmental water testing.


  • Salmonella;
  • Antibody;
  • rRNA;
  • FISH;
  • Enumeration;
  • Detection;
  • Food;
  • Water