Hirudin is a highly effective and very specific anticoagulant which specifically inhibits formation of fibrin and activation of factors V, VIII and , Xenopus/Amphibian,III by forming irreversible, noncovalent 1:1 comple, Xenopus/Amphibian,es with a-thrombin. Hirudin is a 7 kDa protein naturally originating from the medical leech Hirudo medicinalis. The affinity (Kd) of this antibody for rHV2K47 is 3.5, Xenopus/Amphibian,10E-8 M. The antibody reacts with hirudin added to rabbit, rat, dog and monkey plasma.