Platelets are circulating blood cells whose function is central to hemostasis following vascular injury. Platelet activation at inappropriate sites, such as ruptured atherosclerotic plaques, leads to pathogenic thrombus formation, which can result in myocardial infarction and strokes. Platelet dysfunction results in bleeding disorders, of which Glanzmann’s thrombasthenia and Bernard Soulier Syndrome are examples. Following vascular injury or plaque rupture, platelets respond to exposed thrombogenic material via a number of membrane receptors. These interactions, in conjunction with signals from a diverse range of soluble signaling molecules, initiate intracellular signaling events that regulate firm platelet adhesion and lead to platelet activation. Platelet activation constitutes a variety of processes, including degranulation, disruption of membrane lipid asymmetry, shape change, and integrin activation, resulting in platelet crosslinking and the generation of a thrombus.

A wide variety of practical approaches have been developed to study platelet behavior in research and clinical diagnostic laboratories. Such approaches include optical aggregometry, luminescence assays, static adhesion assays, flow cytometry, in vitro whole blood perfusion-based assays, and microscopic analysis using light, confocal, and electron microscopy. The PFA-100 analyzer is also used in clinical assessment of platelet behavior. Studies using these techniques have led to a better understanding of the mechanisms involved in platelet behavior during thrombotic disorders. 

This methods collection will cover platelet function testing approaches, both in primary research and in clinical diagnosis. This will be a repository of protocols that will be available to researchers to assist in addressing biological questions about platelet behavior.