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Two-color assay indicates live and dead sperm cells

This kit enables analysis of sperm viability and fertilizing potential. SYBR® 14 labels live sperm with green fluorescence, and propidium iodide labels membrane-compromised or dead sperm with red fluorescence.

This protocol can be used for:

  • Identifying live and dead sperm using a flow cytometer

This protocol should not be used for:

Assay protocol


1.Dilute semen sample in Live Cell Imaging Solution plus 10% BSA


2. Add 900 µL DMSO to SYBR® 14 dye to make a stock solution


3. Add 1 µL of SYBR® 14 stock solution and 5 µL of propidium iodide solution to 1 mL of diluted semen


4. Incubate for 5–10 minutes at 37°C


5. Analyze on a flow cytometer

Spectral information and storage
  SYBR® 14 Propidium iodide
Excitation/Emission (in nm) 488/516 535/617
Flow cytometer channel FITC RPE
Storage conditions –20°C –20°C

 Protocol tips

  • Phosphate-containing buffers may interfere with SYBR® 14 dye staining
  • Semen dilutions of 1:10 (goat) to 1:40 (bovine) result in acceptable cell densities
  • Dye stock solutions should be stored frozen
Bovine sperm labeled with the LIVE/DEAD® Sperm Viability Kit.