The Platelet Activation Assay is used to compare a test article with a reference-listed drug that is approved for use, for its ability to activate human platelets in an in vitro setting.

Platelet activation happens when an agonist binds to a receptor on the surface of the platelet. This binding causes the platelet to change shape, aggregate with other platelets, and release components of alpha granule membranes (such as P-selectin) into the bloodstream.

In our in vitro Platelet Activation Assay, fresh whole blood that is collected from healthy donors is treated with the test article, positive/negative controls, and a reference-listed drug. We then label the platelets with antibodies (namely anti-CD61, anti-PAC1 and anti-CD62P) that recognize specific proteins on their surface. Platelets would express a glycoprotein which would bind to anti-CD61, however only activated platelets will be able to express PAC1 and anti-CD62P respectively.

Flow cytometry is used to analyze the labeled platelets and evaluate how well the test article induces platelet activation compared to any control drugs. If the test article increases the binding of specific antibodies to platelets, it suggests that the medicine can activate platelets. We also compare the frequencies of inactive and activated platelets in samples treated with the test article versus the reference-listed drug.

This test can be performed both non-GLP or in compliance with Good Laboratory Practice Regulations.