Recalcified whole blood pretreated with either vehicle, 1A6, 14E11, 10C9, CTI or hirudin was perfused over chambers coated with collagen, collagen + 0.01 – 0.1 nM TF, or 0.01 – 0.1 nM TF alone at shear rate of 300 s−1. Samples were collected downstream of the chamber; distal microaggregate formation and single platelet consumption was assessed by FACS (A–E). Results (mean±SEM) from at least 4 experiments.