Patent ID: 8304205

Claim:
A method for determining the activity of a proteolytic coagulation factor of the blood coagulation cascade in a whole blood or plasma sample, the method comprising: (a) providing in combination in a reaction mixture: (i) the sample, and (ii) an activation agent for activating directly or indirectly the proteolytic coagulation factor of the blood coagulation cascade thereby providing an activated proteolytic coagulation factor, (iii) a cleavable moiety which has a cleavage site that is cleavable by the activated proteolytic coagulation factor and wherein the cleavable moiety becomes bound to a chemiluminescent agent and a sensitizer agent, (iv) a chemiluminescent agent comprising a member of a specific binding pair capable of interacting with an antigenic or epitopic site on said cleavable moiety, and (v) a sensitizer agent comprising a member of a specific binding pair capable of interacting with an antigenic or epitopic site on said cleavable moiety, wherein the cleavable moiety is a natural substrate of the activated proteolytic coagulation factor which is contained in the sample and which becomes bound to the chemiluminescent agent and the sensitizer agent in the reaction mixture; and wherein the chemiluminescent agent and the sensitizer agent are related in that, when in close proximity, energization of the sensitizer agent results in energization of the chemiluminescent agent; (b) measuring a chemiluminescent signal and relating the signal to the activity of the proteolytic coagulation factor of the blood coagulation cascade.