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