Platelet Function Tests Cone-and-Platelet Analyzer 200 µL of citrated blood will be placed in a polystyrene well and subjected to a shear rate of 1300 sec-1 using a rotating conical disk for 2 minutes. The well will be washed and stained by May-Gruenwald stain. Platelet adhesion will be evaluated as the percentage of total area covered with platelets designated as surface coverage (%) and aggregation as the mean size of the surface-bound aggregates designated as average size (µ`m2) by use of an image analysis system (Galai).