Measurement of in vitro P-selectin expression by flow cytometry

Sean D. Kennedy, Yasuyuki Igarashi, Thomas S. Kickler

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Measurement of in vivo platelet activation is difficult after phlebotomy and during blood processing for analysis. We used flow cytometry to measure platelet surface expression of P-selectin in the presence and absence of trimethylsphingosine (a platelet activation inhibitor) and compared the results with those from the standard methods of preventing in vitro P- selectin expression. Percent activation was calculated as a ratio of mean sample fluorescence to 100% mean fluorescence after phorbol myristate acetate treatment. Twenty-five micromoles per liter of trimethylsphingosine kept in vitro platelet activation below 5% up to 6 hours after collection and below 10% at 24 hours after collection. Trimethylsphingosine failed to prevent platelet activation caused by centrifugation, storage at 4°C, or stimulation with common agonists. Addition of trimethylsphingosine to whole blood was valuable in preventing in vitro platelet activation. This compound promises to be a useful preservative for diagnostic testing of platelet activation.

Original languageEnglish (US)
Pages (from-to)99-104
Number of pages6
JournalAmerican journal of clinical pathology
Issue number1
StatePublished - Jan 1997


  • Coagulation
  • Flow cytometry
  • Integrins
  • P-selectin
  • Platelet function

ASJC Scopus subject areas

  • Pathology and Forensic Medicine


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