Patent ID: 6994984

Claim:
A method of determining the blood coagulation potential of a body fluid selected from whole blood, citrated or equivalently stabilized blood, and plasma, comprising: (i) contacting an activator reagent with a sample of the body fluid, wherein the reagent reacts with the body fluid, said reagent comprising: (a) a predetermined amount of factor Xa or a hematologically equivalent mutant thereof; and (b) a predetermined amount of factor Va, a hematologically equivalent mutant thereof, or an enzyme which activates endogenous factor V; (ii) if necessary, inducing coagulation by adding one or more coagulation accelerants; and (iii) establishing a value indicative of the coagulation potential, wherein the establishment of the value indicative of the coagulation potential comprises measuring one of the following: (a) the time between the contacting of the activation reagent with or without the coagulation accelerant to said sample and the onset of clotting; (b) the time between the addition of said reagent with or without the coagulation accelerant to said sample and the detection of free thrombin activity; (c) the thrombin activity; and (d) the factor Xa activity, and wherein the time between the addition of said reagent with or without the coagulation accelerant to said sample and the onset of clotting is measured using an optical coagulometer.