The effect of TM on tissue factor-induced coagulation of normal plasma and PCI-deficient plasma. Normal plasma (open symbols) and PCI-deficient plasma (closed symbols) were incubated with buffer (○,•) or 10 (□,▪) or 25 (▵,▴) nmol/L rabbit lung TM (A) or 50 (◊,⧫) or 100 (▿,▾) nmol/L TM4-6 (B). Clotting was initiated by adding recombinant tissue factor and calcium, and the formation of fibrin was measured in time as the change in turbidity at 405 nm.