Appeal No. 1996-1811
Application No. 08/169,968
neutralizing substance. Claim 1 specifies the concentration of these compounds as they
would be present when mixed with a given volume of blood, i.e., about 0.2-3.0 U
thrombin/ml blood mixture, about 0.005-0.2 mg snake venom/ml blood mixture and about
0.02-0.8 mg protamine sulfate (i.e., a heparin neutralizing substance)/ml blood mixture.
Claim 14 recites functional amounts of these three compounds, i.e., thrombin, a generic
heparin neutralizing substance and snake venom capable of converting fibrinogen to fibrin
in “sufficient amounts to rapidly clot ... [a] highly heparinized blood sample." According to
the specification,
[b]y applying this reagent combination in very low concentration it is possible
to clot non anticoagulated blood from normal individuals within two minutes
and blood from patients receiving heparin therapy within five minutes. Prior
to the development of this clot promoting preparation, non anticoagulated
blood required three to five times as long to clot (i.e., 6-10 minutes) and
heparinized blood would not clot for several hours. [Page 6, lines 6-14.]
According to the specification, “[t]ypically highly heparinized blood is between 2-5 units per
milliliter and possibly higher” (page 3, lines 8-9). Claim 20 recites preparation of a clotting
reagent containing 0.5 U thrombin, 0.01 mg snake venom and 0.05 mg protamine sulfate
per ml of reagent.
JP 58-1460 discloses blood collecting tubes containing, as a blood coagulation
(i.e., clot) accelerating agent, either 10-200 µg (i.e., 0.01-0.20 mg) protamine sulfate or 10
µg or more (i.e., 0.01 mg or more) of thrombin-like enzyme contained in snake venom per
ml of added heparinized blood sample (page 4, lines 11-24). “[T]he serum sample could
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Last modified: November 3, 2007