A micromethod to measure platelet aggregation and ATP release by impedance

A standard electrode has been modified in order to detect platelet aggregat ion by impedance in small volumes of whole blood. The modified electrode wa s constructed to fit into a standard 0.5-ml cuvette normally employed for d etecting platelet aggregation in platelet-rich plasma (PRP) on a Chrono-log Aggregometer (Haverford, PA). Whole blood samples were mixed 1:1 with sali ne and total volumes of 1 ml, 500 mul and 300 mul were tested. ATP release was recorded concurrently with aggregation by measuring the luminescence fr om the firefly luciferin-luciferase reaction. The modified electrode could detect aggregation in the 300- and 500-mul samples with the same efficiency as the 1-ml samples. ATP release in the 300- and 500-mul samples yielded e quivalent levels of release as detected with the 1-ml samples. This electro de is well suited for evaluation of platelet function in research and clini cal blood samples where only small volumes of blood are available. (C) 2001 Elsevier Science Ltd. All rights reserved.