Successful determination of platelet lifespan in C3H mice by in vivo biotinylation.

Mice are frequently used as test animals in blood platelet research studies, but safe and convenient methods are not available to easily assess lifespan. Therefore we have improved an existing method for measuring platelet lifespan by determining the disappearance of biotin-labeled platelets from the circulation of mice with immunofluorescence and flow cytometry. In vivo labeling of platelets with Sulfo-NHS-Biotin, a water-soluble moiety, was used as a direct method for labeling the entire platelet population by direct infusion into mice. Platelet samples were collected daily, washed, labeled with a fluorescent detection agent, and analyzed by flow cytometry to measure the percentage of biotinylated cells. This method allowed a rapid determination of murine platelet lifespan without requiring radioactive labels. Using this method, we have estimated that the platelet lifespan in C3H male mice is approximately 4.8 days.