A Micromethod to Measure Platelet Aggregation and ATP Release by Impedance

Abstract

A standard electrode has been modified in order to detect platelet aggregation by impedance in small volumes of whole blood. The modified electrode was constructed to fit into a standard 0.5-ml cuvette normally employed for detecting platelet aggregation in platelet-rich plasma (PRP) on a Chrono-log Aggregometer (Haverford, PA). Whole blood samples were mixed 1:1 with saline and total volumes of 1 ml, 500 μl and 300 μl were tested. ATP release was recorded concurrently with aggregation by measuring the luminescence from the firefly luciferin–luciferase reaction. The modified electrode could detect aggregation in the 300- and 500-μl samples with the same efficiency as the 1-ml samples. ATP release in the 300- and 500-μl samples yielded equivalent levels of release as detected with the 1-ml samples. This electrode is well suited for evaluation of platelet function in research and clinical blood samples where only small volumes of blood are available.