<unk>  is a noninvasive method for testing the quality of platelet-rich plasma (PRP).<unk>  is caused by light diffraction due to the alignment of normal disc-shaped platelets. These discs align light that is diffracted, creating a cloud- or swirl-like appearance. Results of a<unk>  test are recorded as positive or extensive swirl, moderate or intermediate swirl, and absent or negative swirl.
Platelet swirling
Procoagulant platelets
Ristocetin-induced platelet aggregation
Platelet adhesiveness
Erythrocyte aggregation
Endothelial activation
Leukocyte extravasation
Platelet plug