Platelet aggregometry on whole blood: the use of the ELT 8/ds blood cell counter in the investigation of bleeding disorders.

A method is described for measuring platelet aggregation by serial counting of platelets in whole blood, using the Ortho ELT 8/ds blood cell counter. The method is simple, rapid, reproducible and more sensitive to low concentrations of ADP and other agonists than conventional aggregometry on platelet-rich plasma. It can be used as a diagnostic test for disorders of platelet function using as little as 2 ml of whole blood: results in thrombasthenia, Hermansky-Pudlak and Bernard Soulier syndromes and von Willebrand's disease are shown.