The implantation of cardiovascular technologies often leads to an increase in platelet activation as a result of non-biological geometries and high shear stresses, which can lead to thrombosis and clotting. Platelet activation levels can be quantified using flow cytometry by staining activated platelets with fluorophore-conjugated P-Selectin protein specific antibodies. This characterization of platelet activation is crucial in experimentally verifying predictions of platelet agitation that are made using computational fluid dynamics models of cardiovascular devices.