Appeal No. 94-1484
Application 07/536,556
to the use of E. coli B. Appellants argued that the use of this particular strain is
significant in the present invention. See, e.g., the first full paragraph of page 5 of the
Appeal Brief. As stated at page 20 of the specification:
The choice of the host strain is also a critical step in the development of
an efficient method of production. It is, in fact, known that insertion of the
same expression plasmid in different strains can lead to very different
expression efficiencies (Harris T.J.R. and Emtage J.S. Microbiological
Sciences, 3, p. 28-31, 1986).
The Harris reference has not been made of record by either appellants or the examiner.
Furthermore, the specification indicates at page 21 that:
For instance, fermentations at high biomass may dramatically be
influenced by the type of host. The present inventors as well as other
groups of researchers have consistently found that E. coli strains of the
type B can be grown more easily than, e.g., K-12 strains. Insertion of the
same expression plasmids, pFC16 or pFC44, in K-12 strains such as
C600 generates recombinant strains, which cannot grow, in fermentators,
as efficiently as the recombinant B strains. In other words, yields of
recombinant non-glycosilated pro-UK are higher from B strains, when
using the same expression plasmids.
Appellants have not made of record any further information regarding the work of the
“other groups of researchers” who found that E. coli B can consistently be grown more
easily than other E. coli strains.
Upon return of the application, appellants and the examiner should take a step
back and re-evaluate the record, paying special attention to that aspect of the claimed
invention which involves the use of E. coli B. If the work of the “other groups of
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