Appeal No. 2003-0528 Page 4
Application No. 09/314,841
[sic] a convenient, stable, and reliable liquid thromboplastin reagent
with a long shelf life which avoids the turbidity and other problems
inherent to a lyophilized product, as taught by B[utler]….
According to the examiner (Answer, page 5), “[o]ne skilled in the art would also
would have expected success in formulating the liquid reagent of B[rucato] to be
stable for at least two weeks, as taught by B[utler], because B[utler] teaches that
a liquid reagent comprising rabbit thromboplastin, PEG, calcium gluconate, a
propionate salt, BSA, and antimicrobial agents can be formulated to be stable for
up to 20 months … and B[rucato]’s liquid reagent comprises a rabbit
thromboplastin, PEG, calcium gluconate, propionic acid (i.e. propionate salt),
BSA, and antimicrobial agents, as set forth above.” In addition, the examiner
concludes (Answer, page 6):
It also would have been obvious to one of ordinary skill in the art at
the time of invention to have used the beta alanine or GABA of
S[chwinn] as stabilizers in the reagent of B[rucato] and B[utler]
where the motivation would have been to use any amino acid
known to be useful for stabilizing coagulation factor proteins (e.g.
the thromboplastin of B[rucato]), as suggested by S[chwinn]’s
teaching for a variety of amino acids to be used as coagulation
factor stabilizers.
Upon consideration of this record, we cannot agree with the examiner’s
conclusion of obviousness. According to Butler (column 1, lines 33-37), “[t]he
sensitivity of a thromboplastin reagent rests on a number of factors, such as the
final reagent composition, which may include buffers, salts and stabilizers; the
method of extracting the thromboplastin from tissue; and the original source of
the tissue.”
Butler’s invention “is a liquid thromboplastin reagent composed of
thromboplastin tissue extract, calcium ions, stabilizers and antimicrobials. This
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