UNIT 6.24 Flow Rate Calibration for Absolute Cell Counting Rationale and Design

  1. Clare Walker,
  2. David Barnett

Published Online: 1 MAY 2006

DOI: 10.1002/0471142956.cy0624s36

Current Protocols in Cytometry

Current Protocols in Cytometry

How to Cite

Walker, C. and Barnett, D. 2006. Flow Rate Calibration for Absolute Cell Counting Rationale and Design. Current Protocols in Cytometry. 36:6.24:6.24.1–6.24.8.

Author Information

  1. Royal Hallamshire Hospital, Sheffield, United Kingdom

Publication History

  1. Published Online: 1 MAY 2006
  2. Published Print: APR 2006


There is a need for absolute leukocyte enumeration in the clinical setting, and accurate, reliable (and affordable) technology to determine absolute leukocyte counts has been developed. Such technology includes single platform and dual platform approaches. Derivations of these counts commonly incorporate the addition of a known number of latex microsphere beads to a blood sample, although it has been suggested that the addition of beads to a sample may only be required to act as an internal quality control procedure for assessing the pipetting error. This unit provides the technical details for undertaking flow rate calibration that obviates the need to add reference beads to each sample. It is envisaged that this report will provide the basis for subsequent clinical evaluations of this novel approach.


  • flow cytometry;
  • single platform;
  • absolute counts;
  • quality control;
  • CD4+ T lymphocytes