Method for determining the functional activity of free protein s or protein c in a plasma sample

Abstract From the Canadian patent

There is described a method for assaying the functional activity of free Protein S or Protein C in a plasma sample by adding to, the plasma sample a coagulation enzyme FIXa, which enzyme, promotes the formation of coagulation enzyme FXa optionally together with further coagulation factors, whereafter the sample is incubated and the quantity of thrombin formed from prothrombin this, process being promoted by FXa, is measured in a known manner. The level of functionally active Protein S or Protein C which is, inversely correlated to the amount of thrombin formed is then, determined on the basis of the quantity of thrombin measured in a, known manner with the aid of a standard.