Multiplate^® detection principle:

Impedance aggregometry was developed by Cardinal and Flower and has been used since the 1980’s for the
assessment of platelet function in whole blood.

Impedance aggregometry is based on the principle that blood platelets are non-thrombogenic in their resting state, but expose receptors on their surface when they get activated which allow them to attach on vascular injuries and artificial surfaces.

When platelets stick on the Multiplate^® sensor wires, they enhance the electrical resistance between them, which is continuously recorded. In order to enhance the resistance on the sensor wires a tight attachment of the platelets is required.

The fact that aggregation in Multiplate^® takes place on surfaces is a major difference compared to methods such as Born aggregometry and single platelet counting. In Born aggregometry and single platelet counting methods, platelets aggregate with each other in the liquid phase. This presumably happens only in severely ill patients (e.g. during HIT type II and DIC), as coagulation and platelet aggregation in-vivo usually only take place on surfaces (vascular injuries / inflamed vessels / atheromatous plaques).