Abstract: The present invention involves the determination of Protein S and Protein C activity in human plasma based on the addition of FIX.sub.a which indirectly influences the formation of thrombin.

Abstract: The invention relates to a freeze-dried reagent combination containing all reagents required for determination of components active in a proteolysis such as proteases and especially proenzymes, cofactors, inhibitors and activators for proteases which reagent combination is enclosed in a container such as a cuvette. The invention also relates to a new process for the preparation of such a reagent combination in which process the conditions are controlled so that all reagents can exist in one single solution which is freeze-dried without the reagent being deactivated; and the use of the reagent combination in the fields of coagulation and fibrinolysis.