Fig. 3.

Clotting times for a single plasma as a function of coagulation factor concentration. Immunodepleted human plasma was reconstituted at indicated coagulation factor levels and incubated with thromboplastin-coated microspheres at a count of 10⁴ mL⁻¹ for 3 minutes at 37°C prior to recalcification (8.3 mM, final Ca²⁺ concentration). The time for plasma to clot was recorded on a KC4 coagulation analyzer. Experiments were performed in duplicate, with the mean clotting time reported. The data points represent the mean clotting time (n=3–4) and the error bars represent standard error. The gray regions represent the reported range of normal coagulation factor levels.