Ex Parte CROS et al

Board of Patent Appeals and Interferences

Apr 25, 2002

08945731 (B.P.A.I. Apr. 25, 2002)

The opinion in support of the decision being entered today was not written for publication and is not
binding precedent of the Board.

Paper No. 19

UNITED STATES PATENT AND TRADEMARK OFFICE

__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte PHILIPPE CROS, ABDELHAMID ELAISSARI,
CLAUDE MABILAT, CHRISTIAN PICHOT,
MARC RODRIGUE, and LISE SANTORO
__________

Appeal No. 2001-0499
Application No. 08/945,731
__________

HEARD: March 19, 2002
__________

Before WILLIAM F. SMITH, SCHEINER, and GREEN, Administrative Patent Judges.

WILLIAM F. SMITH, Administrative Patent Judge.

VACATUR AND REMAND TO EXAMINER

Having considered the record and listening to oral argument, we conclude that
this case is not in condition for a decision on appeal. Accordingly, we vacate the
examiner’s rejection and remand the application for the examiner to take appropriate
action.
Claim 3 is representative of the subject matter on appeal reads as follows:
3. Process for the isolation in aqueous phase of a nucleic material present in a
sample by adsorption of said nucleic material onto a particulate support, comprising:
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Application No. 08/945,731

(a) providing an adsorption reagent comprising a sol consisting of an aqueous
continuous phase and a discontinuous phase of the particulate support, which
comprises a functionalized, particulate polymer, said polymer being obtained by
polymerization of (1) a first water-soluble monomer of acrylamide or of an acrylamide
derivative, (2) at least one cross-linking agent and (3) at least a second cationic and
water-soluble functional monomer, said polymer having a predetermined lower critical
solubility temperature (LCST) which is between 25 and 450C,
(b) bringing into contact the adsorption reagent with the sample containing the
nucleic material to absorb the nucleic material to the particulate support,
wherein, in said contacting step (b), the reaction medium has:
- an ionic strength at most equal to 10 -2 M,
- a pH at most equal to 7, and
- a temperature less than the LCST of the polymer,
(c) optionally observing that the adsorption has taken place, and
(d) separating the discontinuous phase from the continuous phase.

The references relied upon by the examiner are:
Hoffman et al. (Hoffman) 5,912,032 Mar. 27, 1990
Kausch et al. (Kausch) 5,508,164 Apr. 16, 1996
Kawaguchi et al. (Kawaguchi) 5,122,600 Jun. 16, 1992
Itoh et al. (Itoh) EP 161,881 Nov. 21, 1985
Claims 1 through 3 and 5 through 23 stand rejected under 35 U.S.C. § 103(a).
As evidence of obviousness, the examiner relies upon Itoh, Hoffman, Kausch, and
Kawaguchi.
VACATUR
We begin with the proposition that this board serves as a board of review, not as
a de novo examination tribunal. 35 U.S.C. § 6(b). Review of the examiner’s position in
this appeal is difficult since the examiner has not applied the teachings of the cited prior
art against the requirements of any individual claim on appeal.
At page 4 of the Examiner’s Answer, the examiner refers the reader to Paper No.
10 for a statement of the rejection. Paper No. 10 is an Advisory Action entered on
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November 10, 1999. Therein, the examiner explains why the claims pending at that
time were considered to be unpatentable under 35 U.S.C. § 103(a) on the basis of Itoh,
Hoffman, Kausch, and Kawaguchi. The explanation is unusual in that it is a blend of a
statement of a rejection and an answer to arguments. Be that as it may, the explanation
is difficult to review since the examiner does not refer to any individual claim on appeal
but, rather, couches the explanation in terms of “the claims” or “the instant invention.”
As a result, we have a very general statement as to what purportedly would have been
obvious to one of ordinary skill in the art but not a specific statement as to why claim 3,
the broadest claim pending, would have been obvious to one of ordinary skill in the art.
While the examiner does point to specific disclosures of the four documents in
the explanation, at crucial points in the examiner’s analysis we are left with surmise and
conjecture. For example, the examiner states in the paragraph bridging pages 4-5 of
Paper No. 10:
A further reading of Itoh et al. at page 47, lines 6-24 reveals a teaching of
the general mechanism of action of the polymer. Stating that high molecular
weight substances are retained at low temperatures and released at high
temperatures. While Itoh et al. did not contemplate nucleic acids to be treated in
this manner, it is clear that an understanding of the general mechanism of action
of the polymer is sufficient to teach one of skill in the art how to use the polymer.

Another example appears at page 5 of Paper No. 10 where the examiner states that
“the general teachings of Itoh … are sufficient to teach one of skill in the art how to use
the polymer ….”
The vagueness and lack of specificity of the examiner’s position is perhaps
pointed up most succinctly in the paragraph bridging pages 6-7 of Paper No. 10 which
reads as follows:
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It would have been obvious to one of ordinary skill in the art at the time of
the instant invention to combine the teachings of Itoh et al., Hoffman et al.,
Kawaguchi et al. and Kausch et al. to produce the instant invention because Itoh
et al., Hoffman et al., Kawaguchi et al. and Kausch et al. were all using
acrylamide polymers with a copolymer which would adsorb and desorb nucleic
acids and proteins. Itoh et al. taught the use of the acrylamide polymer in bead
form, and coated onto solid supports. Hoffman et al. taught the adsorption of
nucleic acid in a low ionic strength buffer and the desorption of the nucleic acid in
a high ionic strength buffer. Kawaguchi et al. and Kausch et al. taught the
coating of polyacrylamide onto solid bead supports, and Kausch et al. taught the
polyacrylamide coated beads which comprised a magnetic compound to facilitate
the isolation of the bead with the bound DNA in a magnetic field.

That paragraph begs the question what is the “instant invention?” Patentability is
determined based upon the individual claims pending in an application, not an
“invention.” In other words, examiners do not examine the “invention” to determine
whether an applicant is entitled to a patent under Title 35 of the United States Code.
Rather, the examination is based on the individual claims appearing in the patent
application. The lack of specificity in the examiner’s statement is also highlighted in this
paragraph in that Kawaguchi and Kausch are relied upon to teach coating of
polyacrylamide onto solid bead supports and polyacrylamide coated beads comprised
of a magnetic compound respectively. Neither of these requirements is found in claim 3
on appeal.
An example of an unsupported assertion made by the examiner is found at page
4 of Paper No. 10 where the examiner states:
While Itoh et al. did not specifically teach the use of a low ionic strength
binding buffer nor the increased ionic strength of an eluting buffer, one of
ordinary skill in the art would know that the use of an affinity matrix would require
the use of elements such as a low ionic strength binding buffer and an increased
ionic strength buffer to elute the bound nucleic material.

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Application No. 08/945,731

Another example appears in the paragraph bridging pages 4-5 of Paper No. 10 as
follows:
A further reading of Itoh et al. at page 47, lines 6-24 reveals a teaching of
the general mechanism of action of the polymer. Stating that high molecular
weight substances are retained at low temperatures and released at high
temperatures. While Itoh et al. did not contemplate nucleic acids to be treated in
this manner, it is clear that an understanding of the general mechanism of action
of the polymer is sufficient to teach one of skill in the art how to use the polymer.

It is clear from reading Itoh that it is relevant in determining the patentability of
claim 3 on appeal. However, in critical passages, Itoh contradicts or is opposite that
which is required by claim 3 on appeal. For example, claim 3 requires that the nucleic
material be absorbed at a lower temperature and be released at a higher temperature.
In the one mention of nucleic acids in Itoh, the reference states that “these compounds
may be held at high temperatures and released at low temperatures.” Itoh, page 44,
line 13- page 45, line 13. However, as observed by examiner and appellants, Itoh goes
on to state at page 47, lines 19-24 that:
Where materials, which are to be released, are held in gel-like polymers,
they are held at low temperatures as the gel-like polymers are swollen at the low
temperatures and are released at high temperatures as the gel-like polymers are
shrunk at the high temperatures.

It may be that a person of ordinary skill in this art reading Itoh in its entirety would
reasonably conclude that regardless of the other teachings in the document, when gel-
like polymers are used according to that invention, they absorb at a low temperature
and release at a high temperature similar to the polymer sol required by claim 3 on
appeal. If so, then one of ordinary skill in the art would understand that the specific
teaching in regard to absorption and release of nucleic acids at page 45 of the
document, which is opposite that required by claim 3 on appeal would apply only when
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Application No. 08/945,731

non-gel-like polymers are used in Itoh. We do not have such a finding from the
examiner.
As a final example of the difficulty of reviewing the examiner’s position, we point
to the claim requirement that the polymer contain a second, cationic monomer. The
examiner states at page 8 of Paper No. 10 that Itoh teaches the use of cationic
monomers at page 24, lines 11-21. However, that passage of Itoh is directed to
homopolymers and copolymers which contain carboxylic acid groups. It is not readily
seen how those polymers would be considered cationic. However, that is not to say
Itoh does not specifically address the issue. Itoh states at page 50 that a “more
selective holding and release” can occur if an ionic monomer, such as a cationic
monmer is is used in the polymer. If nucleic acids are anionic in nature, this latter
passage from Itoh may supply the requisite reason, suggestion, or motivation to use a
cationic, gel copolymer as otherwise described in Itoh to separate nucleic acids by
absorbing at a low temperature and releasing at a high temperature. Again, we do not
have such findings and conclusions from the examiner.
The Court of Appeals for the Federal Circuit reviews board decisions. 35 U.S.C.
§ 144. The court discussed their statutory duty of review in Gechter v. Davidson, 116
F.3d 1454, 43 USPQ2d 1030 (Fed. Cir. 1997). In considering the issue, the court
stated “the statute’s mandate to ‘review’ implies inherent power in this court to require
that the Board’s decision be capable of review.” Id., F.3d at 1457, 43 USPQ2d at 1033.
The court observed “Necessary findings must be expressed with sufficient particularity
to enable our court, without resort to speculation, to understand the reasoning of the
Board, and to determine whether it applied the law correctly and whether the evidence
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Application No. 08/945,731

supported the underlying and ultimate fact findings.” Id. What the Federal Circuit
rightfully expects from the Board, the Board expects from the examiner.
Under these circumstances, it is appropriate to vacate the rejection and return
the case to the jurisdiction of the examiner to reconsider the patentability of the claims.
REMAND
Upon return of the application the examiner should take a step back and
reassess the patentability of the claims. The reassessment should take place on a
claim-by-claim basis beginning with claim 3. If the examiner believes that claim 3 is
unpatentable on the basis of Itoh and/or other relevant prior art, he should state the
facts and reasons used in support with particularity.
There is other evidence of record which may be relevant in putting Itoh in proper
factual context to the extent it describes the separation of nucleic material. We refer to
European Patent Application No. 0 501 301 A2, Mori, of record. Mori describes an
electrophoretic gel comprising at least one cross-linked temperature-responsive
polymeric compound having an LCST used to separate nucleic acids. As described by
Mori, the acrylamide based gels of that reference are used to absorb nucleic acids at
low temperatures and release the absorbed material at high temperatures. See, e.g.,
column 6, lines 31-54. This information may provide evidence that Itoh’s disclosure that
gel polymers absorb at a low temperature and release at a high temperature does apply
to nucleic acids and thus provides an answer to appellants’ argument that Itoh is to be
read restrictively as only teaching absorbing nucleic acids at high temperature and
releasing at low temperatures.
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Application No. 08/945,731

To the extent Itoh and other relevant references teach that absorption and
release of valuable substances using LCST polymers depends on temperature, pH and
ionic strength1 but do not specifically teach the specific parameters required by the
claims on appeal, the examiner should determine if such parameters are result effective
variables. If so, optimization of such values may have been obvious. In re Boesch, 617
F.2d 272, 276, 205 USPQ 215, 219 (CCPA 1980).
FUTURE PROCEEDINGS
We state that we are not authorizing a supplemental examiner’s answer under 37
CFR § 1.193(b)(1).
VACATED; REMANDED

)
William F. Smith )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
Toni R. Scheiner )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
Lora M. Green )
Administrative Patent Judge )

ELD

1 See Hoffman, column 1, lines 25-39 (LCST polymers undergo phase separation in response to change
in solution pH, ionic strength or temperature.).
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Application No. 08/945,731

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