Reconstitution of protein C–deficient plasma in the absence or presence of TM. Plasma deficient in protein C was incubated with buffer (○,•) or 40 (□,▪), 80 (▵,▴) or 160 (▿,▾) nmol/L protein C in the absence (A, open symbols) or presence (B, closed symbols) of TM (25 nmol/L). Fibrin formation was monitored as the change in turbidity at 405 nm after addition of recombinant tissue factor (Innovin, diluted by a factor 3 × 10⁴) and calcium required for recalcification. Please note the difference in x-axis scales in (A and B).