{HEAD ~ An activation reaction} of {TAIL ~ the blood coagulation factor} XII is initiated by adding a blood coagulation factor XII activator to an animal plasma in the presence of the tested substance 
of
{ HEAD ~ An activation reaction } of { TAIL ~ the blood coagulation factor } XII is initiated by adding a blood coagulation factor XII activator to an animal plasma in the presence of the tested substance
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH