UNIT 7.38 Dual-Pulse Labeling Using 5-Ethynyl-2′-Deoxyuridine (EdU) and 5-Bromo-2′-Deoxyuridine (BrdU) in Flow Cytometry

  1. Jolene A. Bradford,
  2. Scott T. Clarke

Published Online: 1 JAN 2011

DOI: 10.1002/0471142956.cy0738s55

Current Protocols in Cytometry

Current Protocols in Cytometry

How to Cite

Bradford, J. A. and Clarke, S. T. 2011. Dual-Pulse Labeling Using 5-Ethynyl-2′-Deoxyuridine (EdU) and 5-Bromo-2′-Deoxyuridine (BrdU) in Flow Cytometry. Current Protocols in Cytometry. 55:7.38:7.38.1–7.38.15.

Author Information

  1. Life Technologies, Eugene, Oregon

Publication History

  1. Published Online: 1 JAN 2011
  2. Published Print: JAN 2011


Changes in DNA replication during S-phase can give insights into mechanisms of cell growth, cell cycle kinetics, and cytotoxicity. A common method for detection of cell proliferation utilizes the incorporation of a thymidine analog during DNA synthesis. Incorporation of multiple analogs at different time points can further define cell cycle kinetics. Traditionally, the dual-pulse method has been done by combining 5-bromo-2′-deoxyuridine (BrdU) with iododeoxyuridine or chlorodeoxyuridine, with detection using multiple cross-reacting BrdU antibodies. This unit presents a dual-pulse method using the thymidine analog 5-ethyl-2′-deoxyuridine (EdU), detected by click chemistry, combined with BrdU labeling and detection. No cross reactivity with incorporated EdU is observed using the BrdU antibody clone MoBU-1. EdU detection using click chemistry does not cross-react with incorporated BrdU. Cells are first pulsed with EdU, and then pulsed with BrdU; sequential pulses of EdU, followed by BrdU, are done without removing or washing out EdU. Curr. Protoc. Cytom. 55:7.38.1-7.38.15. © 2011 by John Wiley & Sons, Inc.


  • BrdU;
  • EdU;
  • S-phase;
  • click chemistry;
  • dual pulse;
  • proliferation;
  • thymidine analog