The test involves drawing a blood sample from the patient and placing it into the analyzer. The blood is then passed through a membrane with a small aperture. As platelets interact with the collagen and agonist-coated membrane, they start to occlude the aperture, and the time taken for this occlusion is recorded. This measurement is known as the closure time (CT). The PFA 100 test provides two types of closure times: CT-Epi (using epinephrine) and CT-ADP (using ADP).
