UNIT 1.23 Pulse Width for Particle Sizing

  1. Robert A. Hoffman

Published Online: 1 OCT 2009

DOI: 10.1002/0471142956.cy0123s50

Current Protocols in Cytometry

Current Protocols in Cytometry

How to Cite

Hoffman, R. A. 2009. Pulse Width for Particle Sizing. Current Protocols in Cytometry. 50:1.23:1.23.1–1.23.17.

Author Information

  1. BD Biosciences, San Jose, California

Publication History

  1. Published Online: 1 OCT 2009
  2. Published Print: OCT 2009


The widths of optical pulses in flow cytometry contain information about the size of particles. This size information is independent of many of the factors that affect light scatter as a measure of particle size, and any light scatter or fluorescence signal can be used to measure pulse width. For fluorescence signals, the pulse width can be predicted theoretically for many particle shapes, and quantitative size calibration is possible. To be a meaningful independent parameter, the pulse-width measurement must be independent of the pulse amplitude. This unit provides protocols for determining the signal range over which amplitude independent pulse-width measurements can be made and methods for calibrating the pulse-width measurements to particle diameter. Calibration and application examples are provided and briefly discussed. Curr. Protoc. Cytom. 50:1.23.1-1.23.17. © 2009 by John Wiley & Sons, Inc.


  • pulse width;
  • flow cytometry;
  • size;
  • fluorescence;
  • light scatter