The University of Iowa Carver College of Medicine

Flow Cytometry Facility

Annexin V Plus Propidium
    Iodide for Apoptosis


  • 2.5µg/ml Annexin V (FITC) [final concentration]
  • Binding Buffer
  • HEPES buffer: 10mM HEPES / NaOH, pH 7.4
  • 150mM NaCl
  • 5mM MgCl2
  • 5mM KCl
  • 1.8mM CaCl2
  • 50µg/ml PI (propidium iodide, Sigma Chemical cat# P-4170) in 1 x PBS


Annexin Histogram

Sample histogram using this protocol

  1. Resuspend 5 x 105 cells in 500µl HEPES buffer.
  2. Add 2.5µg/ml Annexin V (FITC) [final concentration].
  3. Incubate at room temperature for 10 to 15 minutes.
  4. Add 10µl PI.
  5. Run on flow cytometer.