Washed platelets from cellubrevin/VAMP-3 knockout mice show normal aggregation. Washed platelets from wild-type (+/+) and cellubrevin/VAMP-3 knockout mice (–/–) were collected from citrated PRP by centrifugation and resuspended in HEPES/Tyrode buffer to a concentration of 3.5 × 10⁵ platelets/μL. Platelets were incubated at 37°C for 5 minutes prior to addition of agonist. Aggregation was measured as an increase in light transmission versus time.