Ex Parte Yang et al

Board of Patent Appeals and Interferences

Feb 24, 2010

10742590 (B.P.A.I. Feb. 24, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
10/742,590 12/19/2003 Kaiyuan Yang KCX-729 (18104) 3937
22827 7590 02/24/2010
DORITY & MANNING, P.A.
POST OFFICE BOX 1449
GREENVILLE, SC 29602-1449
EXAMINER
YU, MELANIE J
ART UNIT PAPER NUMBER
1641
MAIL DATE DELIVERY MODE
02/24/2010 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte KAIYUAN YANG, RAMESHBABU BOGA,
SHAWN RAY FEASTER, ROSANN MARIE KAYLOR, and
DAVID SAMUEL COHEN
__________

Appeal 2009-010236
Application 10/742,590
Technology Center 1600
__________

Decided: February 24, 2010
__________

Before TONI R. SCHEINER, ERIC GRIMES, and STEPHEN WALSH,
Administrative Patent Judges.

GRIMES, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving methods of forming
flow-through assay devices. The Examiner has rejected the claims as
obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.
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STATEMENT OF THE CASE
The Specification discloses that “flow-through electrochemical
biosensors designed to detect the presence of an analyte” are known in the
art (Spec. 1). The Specification also discloses that “traditional flow-through
assay devices require a large sample volume…. Moreover, the contact of the
sample with the working electrode surface is not always sufficient.” (Id.)
The Specification discloses that these problems can be avoided by using a
“flow-through assay device compris[ing] a fluidic microchannel printed onto
a substrate that facilitates the flow of the test sample to a detection working
electrode” (id. at 3).
Claims 50, 53, 54, 56-76, 78-89 and 92-97 are pending and on appeal.
Claim 53 is representative and reads as follows:
53. A method of forming a flow-through assay device for detecting
the presence or quantity of an analyte residing in a test sample, said method
comprising:
i) printing a composition onto a surface of a substrate, the composition
comprising a monomer or prepolymer;
ii) curing the composition to form a fluidic channel, wherein said
channel has opposing walls that are raised above the surface of the substrate;
iii) forming a detection working electrode, said detection working
electrode being in fluid communication with said fluidic channel; and
iv) treating a surface of said detection working electrode with a
specific binding capture ligand for the analyte.

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OBVIOUSNESS
Issue
The Examiner has rejected claims 50, 53, 56-65,1 68-75 and 92-95
under 35 U.S.C. § 103(a) as obvious in view of Bredehorst,2 Kim,3 and
Zhang.4 The Examiner has also rejected claims 54, 76, 78-83, 85-89, 96 and
97 under 35 U.S.C. § 103(a) as obvious in view of Bredehorst, Kim, Zhang
and Wang;5 and claims 66, 67 and 84 under 35 U.S.C. § 103(a) as obvious in
view of Bredehorst, Kim, Zhang, Wang, and Kagan.6 Appellants rely on the
same arguments with respect to all of the rejections. We can therefore
consider them together. In addition, the claims have not been argued
separately and therefore stand or fall together. 37 C.F.R. § 41.37(c)(1)(vii).
The Examiner finds that Bredehorst discloses a method of forming a
flow-through assay device comprising all the steps of claim 53 except “the
method of applying the polymer precursor involving a printing and curing
step” (Ans. 4). The Examiner finds that Kim discloses “printing a polymer
precursor on a substrate … [and] curing the composition … to form a
channel …, wherein the channel has opposing walls that are raised above the
surface of the substrate” (id. at 5), because Kim’s method of “applying the
prepolymer to a mold and removing the mold is a form of printing” (id.).
The Examiner finds that Zhang discloses a detection working electrode in an

1 The Examiner’s statement of the rejection (Ans. 4) does not include claims
64 and 65 but that omission appears to be a typographical error, because the
Examiner includes those claims in the discussion of the rejection (id. at 6).
2 Bredehorst et al., US 6,881,379 B1, Apr. 19, 2005
3 Kim et al., US 6,355,198 B1, Mar. 12, 2002
4 Zhang et al., US 6,670,115 B1, Dec. 30, 2003
5 Wang, Jr. et al., US 5,114,520, May 19, 1992
6 Kagan et al., US 6,887,332 B1, May 3, 2005
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assay device (id.). The Examiner concludes that it “would have been
obvious to one having ordinary skill in the art … to include in the method of
Bredehorst et al., applying the polymer precursor by printing and curing as
taught by Kim et al., in order to provide a polymeric structure that is
patterned with excellent precision and is easily manipulated” (id.).
Appellants contend that the Examiner erred in finding that the cited
references suggest printing and curing a prepolymer or monomer
composition on a substrate to form a channel (Appeal Br. 6-9) and that one
of skill in the art would not have been motivated to combine the cited
references (id. at 9-13).
The issue with respect to this rejection is: Does the evidence of record
support the Examiner’s conclusion that one of skill in the art would have
been motivated to combine the cited references, and that doing so would
lead a skilled worker to a method meeting the limitations of claim 53?
Findings of Fact
1. The Specification discloses that “[p]rinting techniques are
generally utilized in the present invention to apply the sample channel 14 to
the substrate.… For example, in one embodiment, ‘stamp printing’ is
utilized to apply the sample channel 14 to the substrate 40.” (Spec. 8.)
2. The Specification discloses that the “stamp may have raised
features to match the desired channel pattern so that a direct transfer of the
channel-forming material would occur on the substrate 40” (id. at 10).
3. Bredehorst discloses
a method of fabricating a detection system for detecting various
analytes … characterized by the following steps[:]
(a) providing a planar or essentially planar substrate with
sensors for the chemical, optical or electrical detection,
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(b) applying a layer to the substrate, said layer being either
already micropatterned or applying a continuous layer to the
substrate and micropatterning the layer, in each case in such a
way that disjunct regions of the substrate are not covered by the
layer…,
(c) bringing at least part of the uncovered regions into
contact with at least one liquid which contains capturing
molecules, in such a way that the capturing molecules are
capable of adhering to the substrate surface …,
(d) removing the non-adhering constituents of the liquid,
(e) removing the micropatterned layer or parts of said layer.
(Bredehorst, col. 4, ll. 20-44.)
4. Bredehorst discloses that step (e) in the above process is optional
(id. at col. 5, ll. 40-46).
5. Bredehorst discloses that the compartments of its device can be
fabricated “in the form of so-called microcapillary reactors ... consist[ing] of
two microcompartments 11 and 12 … connected to one another via a
capillary-like channel 13” (id. at col. 12, ll. 13-18).
6. Bredehorst discloses that “the microcapillary reactors can remain
on the substrate even during detection of the analytes” (id. at col. 12, ll. 62-
col. 13, l. 1).
7. Bredehorst discloses that
a polymer or its precursor can be used to generate the
microcompartments according to step (b), said polymer being
applied in liquid or paste-like form…. This polymer layer can
be patterned photochemically according to known techniques.
… This method is particularly suitable for producing micro-
compartment patterns in which trench-like depressions around
the bioarrays proper are to remain.
(Id. at col. 9, l. 59-col. 10, l. 10.)
8. Bredehorst discloses that the sensors are preferably “made of
transducers, e.g. electrodes” (id. at col. 5, ll. 20-22).
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9. Bredehorst discloses that stamp printing techniques are known in
the art for forming patterned arrays (id. at col. 1, ll. 58-66) and that
“[d]rawbacks of the stamp techniques include inadequate edge precision and
inhomogeneities in the areal distribution of the molecules, particularly as the
stamp area increases” (id. at col. 2, ll. 22-24.)
10. Kim discloses “techniques for derivatizing surfaces, biologically,
chemically, or physically, according to predetermined patterns” (Kim, col. 4,
ll. 36-38).
11. Kim discloses that the
method involves providing an article having a contoured
surface including at least one indentation defining a pattern and
forming at a first region proximate the substrate surface, in a
pattern corresponding to the indentation pattern, a fluid
precursor of the species. The fluid precursor is allowed to
harden at the first region of the substrate surface in a pattern
corresponding to the indentation pattern.
(Id. at col. 4, ll. 44-54.)
12. Figure 15 of Kim is shown below (in part):

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Figure 15 shows schematically a technique “for forming a waveguide array
or other structure, from a fluid precursor, on a substrate surface” (id. at col.
9, ll. 9-12).
13. Kim discloses that the fluid precursor may be “a hardenable
prepolymeric fluid that is hardened at the surface to form a patterned
polymeric article” (id. at col. 10, ll. 35-37).
14. Kim discloses that the prepolymeric fluid “can be thermally
polymerized on substrate surface 28” (id. at col. 11, ll. 38-45).
15. Kim discloses that “a surface having a pattern of biological agent
compounded therein is produced, and can serve as a sensor for a biological
binding partner of the biological agent” (id. at col. 12, ll. 42-45).
16. Zhang discloses “devices comprising electrosensors containing
capture reagents, their preparation thereof, and their use for detecting …
analyte in a liquid sample” (Zhang, abstract).
17. Zhang discloses that an “electrosensor, e.g., electroimmunosensor,
utilizes a sensor assembly (i.e., sensor strip).… A capture reagent that is
capable of binding to the analyte is immobilized on the working electrode
surface.” (Id. at col. 3, ll. 46-51.)
Principles of Law
“[D]uring examination proceedings, claims are given their broadest
reasonable interpretation consistent with the specification.” In re Hyatt, 211
F.3d 1367, 1372 (Fed. Cir. 2000).
“[W]hen the question is whether a patent claiming the combination of
elements of prior art is obvious,” the answer depends on “whether the
improvement is more than the predictable use of prior art elements according
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to their established functions.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
417 (2007).
The obviousness analysis “can take account of the inferences and
creative steps that a person of ordinary skill in the art would employ.” Id. at
418.
“[I]n general, a reference will teach away if it suggests that the line of
development flowing from the reference’s disclosure is unlikely to be
productive of the result sought by the applicant.” In re Gurley, 27 F.3d 551,
553 (Fed. Cir. 1994).
“[I]n a section 103 inquiry, ‘the fact that a specific [embodiment] is
taught to be preferred is not controlling, since all disclosures of the prior art,
including unpreferred embodiments, must be considered.’” Merck & Co.
Inc. v. Biocraft Labs. Inc., 874 F.2d 804, 807 (Fed. Cir. 1989).
Analysis
Claim 53 is directed to a method of forming a flow-through assay
device comprising the steps of printing a monomer or prepolymer
composition onto a substrate, curing the composition to form a channel with
raised walls, forming a detection working electrode in fluid communication
with the channel, and treating a surface of the detection working electrode
with a ligand that specifically binds the analyte.
Bredehorst discloses a flow-through assay device for detecting an
analyte using a polymer composition formatted on a substrate surface that
may be in the form of a fluidic channel. Bredehorst also discloses a
detection electrode with a capture ligand for the analyte. Kim discloses
formatting microcomponents such as sensors by polymerization of a
prepolymer deposited in a pattern on a substrate, and Zhang discloses that a
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detection electrode comprises a detection working electrode. In view of
these disclosures, it would have been obvious to one of skill in the art to
modify the process of Bredehorst by depositing a prepolymer in a pattern on
the substrate, as taught by Kim, and curing the prepolymer to form the
channels of Bredehorst’s device. The combination requires only the
predictable use of prior art elements according to their established functions.
Appellants argue that Kim does not disclose “printing” a polymer on a
substrate surface to form a channel, because “[a]pplying prepolymer in a
mold and removing the mold as required by Kim et al. is simply not a form
of printing as contemplated by the present disclosure” (Appeal Br. 8).
This argument is not persuasive. The USPTO gives claims their
broadest reasonable interpretation in view of the Specification. The
Specification discloses that stamp printing may be used to transfer the
sample channel to the substrate, and that the stamp may or may not have
raised features corresponding to the channel pattern. Figure 15 of Kim
shows a template having prepolymer in indentations rather than on raised
portions. Thus, one of skill in the art would reasonably interpret a “stamp
printing” process to include the process disclosed by Kim.
Appellants also argue that one of skill in the art would not have a
reason to combine the cited references (Appeal Br. 11-13), because “[t]here
has simply been no reason provided why one of ordinary skill would have
been prompted to modify the teachings of Zhang et al. to arrive at the
claimed invention” (id. at 13).
This argument is not persuasive. Bredehorst and Kim both disclose
devices comprising a polymer on a substrate, and methods of making them.
Bredehorst discloses that its device can be made by applying a liquid
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polymer to a substrate; Kim discloses a method of applying liquid
prepolymer to a substrate, then polymerizing it. Using the polymer-
formatting method of Kim to make the substrate-and-formatted-polymer
assay device of Bredehorst only requires using Kim’s method for its known
function. One of skill in the art would understand that formatting a polymer
by polymerization is an alternative to formatting a polymer by, for example,
photochemical techniques as disclosed in Bredehorst. Appellants’ argument
that one of skill in the art would not have been motivated to modify Zhang to
arrive at the claimed invention is not persuasive because the Examiner relies
on Zhang only for its teaching that a detection electrode typically comprises
a working electrode with an immobilized capture molecule.
Finally, Appellants argue that Bredehorst teaches away from stamp
printing and microcontact printing techniques for formatting a planar
substrate (Appeal Br. 9-11).
This argument is not persuasive. Bredehorst makes clear that stamp
printing is a known technique for formatting substrate surfaces. The fact
that stamp printing was known to have drawbacks, or was not the preferred
embodiment under certain circumstances, would not lead one of skill in the
art away from using it because stamp printing was an art-recognized method
for depositing a polymer on a substrate.
Conclusion of Law
The evidence of record supports the Examiner’s conclusion that one
of skill in the art would have been motivated to combine the cited
references, and that doing so would lead a skilled worker to a method
meeting the limitations of claim 53.
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SUMMARY
We affirm the rejections of claims 50, 53, 54, 56-76, 78-89 and 92-97
under 35 U.S.C. § 103(a).
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED

lp

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