FV titration of thrombin generation in FV-deficient plasma. Plasma from patient GK 502 was reconstituted with 0 to 23 nM purified FV (0%, 0.5%, 1%, 1.5%, 3%, 5%, 10%, 25%, 50%, 75%, and 100% of the normal plasma concentration), and thrombin generation was determined at 13.6 pM TF. Thrombin generation curves obtained at 25%, 50%, 75%, and 100% FV are perfectly superimposable. Inset shows peak height of thrombin generation as a function of FV concentration.