Platelet swirling

Platelet swirling is a noninvasive method for testing the quality of platelet-rich plasma (PRP).^[1] Platelet swirling 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.^{[citation needed]}

Platelet swirling
Purpose	testing the quality of platelet-rich plasma

Results of a platelet swirling test are recorded as positive or extensive swirl, moderate or intermediate swirl, and absent or negative swirl.^{[citation needed]}