Abstract: A method is provided for determining in real time the course of thrombin activity in a sample of blood or plasma as it appears in and disappears from the simple which comprises adding a thrombin substrate to the sample that, per unit time, produces a detectable signal in a quantity that bears relation to the amount of thrombin present. Simultaneously, in a control sample of the same blood or plasma in which thrombin generation is not triggered, the activity of a standard preparation with invariable thrombin activity is measured. The exact molar amount of thrombin present at any moment is obtained by comparison of the activity measured in clotting blood and the simultaneously measured calibrator. The method is useful inter alia for diagnosing hyper- and hypo-coaguable states, either congenital, acquired or drug-induced in humans and animals. Also provided is a kit for use in this method.

Abstract: A method for determining the endogenous thrombin potential (ETP), which shows how much and for what length of time thrombin has been active in a sample of clotting blood or plasma. The ETP can be used for determining the effectiveness of treatment with antithrombotics of any type. Thus, the ETP determination comprises adding to a sample a thrombin substrate, an activator of thrombin formation, a preparation of proteaseinhibitor and if desired a pharmaceutical for analysis. The thrombin substrate is preferably selected to not completely consume the amount of thrombin generated in the sample, to have a rate of conversion of the substrate which is proportional to the amount of thrombin present and to have a measurable conversion product resulting from the conversion by thrombin. Determination of the amount of conversion product leads to determination of the ETP.