Patent ID: 7785820

Claim:
A method for determining the endogenous thrombin potential (ETP) of a sample of coagulating blood or plasma, comprising a) contacting a thrombin substrate with the sample of coagulating blood or plasma, b) allowing cleavage of the thrombin substrate to occur, c) measuring turnover kinetics of the thrombin substrate as a function of time, wherein the turnover kinetics comprise a saturation phase, and wherein the saturation phase comprises a linear region, and d) determining the ETP; wherein the ETP is determined by: i) determining the linear region of the saturation phase of the turnover kinetics within a time window, ii) calculating the slope of the linear region of part (i), which slope corresponds to the slope of α 2 MT kinetics; iii) iteratively determining the binding constant of thrombin to α 2 macroglobulin using slope and kinetics values, wherein the slope consists of said slope of the linear region of the saturation phase; iv) determining values of the kinetics of free thrombin by (1) determining values of the α 2 MT kinetics from the binding constant of thrombin to α 2 macroglobulin, and (2) subtracting the values of the α 2 MT kinetics from the corresponding values of the turnover kinetics; and iv) determining the raw ETP value by averaging the values of the kinetics of free thrombin in the linear region of the saturation phase of the turnover kinetics.