VerifyNow

Associate Editors-in-Chief: Davide Capodanno, M.D. [mailto:Davide.Capodanno@jax.ufl.edu]

Overview
The VerifyNow system (Accumetrics, San Diego, Ca, USA; ) is a bedside test that allows for monitoring of the efficacy of thienopyridines, aspirin, and glycoprotein IIbIIIa inhibitors. Formerly known as the Ultegra rapid platelet function analyzer, the VerifyNow system is a turbidimetric based optical detection system which measures platelet induced aggregation as an increase in light transmittance. This system is a point-of-care and consists of an instrument, a disposable assay device and controls. The assay device contains a lyophilized preparation of human fibrinogen-coated beads, platelet agonist, preservative and buffer. Three assays are currently available, which differ according to the platelet agonist contained in the mixing chamber:

After activation, the GP IIb/IIIa receptors on platelets will bind to the fibrinogen-coated microbeads and cross link to other microbeads resulting in a clearing of the beads and platelets within the detection well. The instrument uses light transmittance to measure the rate at which this clearing occurs. The main advantage of this test is that the patient sample is a low sample volume of 3.2% citrated whole blood, which is automatically dispensed from the blood collection tube into the assay device by the instrument, with no blood handling required by the user. Another advantage is that the instrument provides the results in minutes.