       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

  BASF AGRO B.V., ARNHEM (NL), WADENSWIL
                  BRANCH,
              Plaintiff-Appellant,

                         AND


                   BAYER S.A.S.,
                  Plaintiff-Appellant,

                           v.

MAKHTESHIM AGAN OF NORTH AMERICA, INC.
     AND CONTROL SOLUTIONS, INC.,
           Defendants-Appellees.
          ______________________

                      2012-1206
                ______________________

   Appeal from the United States District Court for the
Middle District of North Carolina in No. 10-CV-0276,
Judge William L. Osteen, Jr.
                ______________________

               Decided: March 20, 2013
               ______________________

 KENNETH A. GALLO, Paul Weiss, Rifkind, Wharton &
Garrison LLP, of Washington, DC, argued for plaintiffs-
2                           BASF AGRO   v. MAKHTESHIM AGAN

appellants. With him on the brief were JOHN E. NATHAN,
CATHERINE NYARADY, KRIPA RAMAN, BRIAN P. EGAN, ERIN
WIGGINS and CASSIUS SIMS, of New York, New York. Of
counsel on the brief were ROBERT J. KOCH, Milbank,
Tweed, Hadley & McCloy, LLP, of Washington, DC, and
PRESSLY M. MILLEN, Womble Carlyle Sandridge & Rice,
LLP, of Raleigh, North Carolina. Of counsel was KENT E.
KEMENY, Paul Weiss, Rifkind, Wharton & Garrison LLP,
of Washington, DC.

 HENRY C. DINGER, Goodwin Procter, LLP, of Boston,
Massachusetts, argued for defendants-appellees. With
him on the brief were MARTA E. GROSS and JOSEPH B.
CRYSTAL, of New York, New York, and APRIL E. ABELE, of
San Francisco, California.
                ______________________
 Before REYNA, BRYSON, ∗ and WALLACH, Circuit Judges.
REYNA, Circuit Judge.
    This is an appeal from a final judgment of the United
States District Court for the Middle District of North
Carolina (“district court”) granting summary judgment of
non-infringement for defendants Makhteshim Agan of
North America and Control Solutions, Inc. (collectively,
“MANA”).
    Plaintiffs Bayer S.A.S. and its exclusive licensee
BASF Agro B.V., Arnhem (NL), Wadenswil Branch (col-
lectively, “BASF”) sued MANA for infringement of two
patents covering a method of applying insecticide to
protect against termites. The district court construed the
claims of the patents. In view of language in the patents
and representations made by the patentee to the Patent
Office, the district court determined that the patentee had
disclaimed certain methods of application. Based on its

    ∗ Judge Bryson assumed senior status on January
7, 2013.
 BASF AGRO   v. MAKHTESHIM AGAN                         3
claim construction, the district court granted summary
judgment of non-infringement for MANA.
    Because the district court correctly construed the
claims of the patents, and because under the correct
construction MANA’s accused product does not infringe,
we affirm.
                  I. PROCEDURAL POSTURE
    In 2010, BASF sued MANA for infringement of two
U.S. patents related to a method for applying insecticide
in and around a building: U.S. Patent Nos. 6,414,010 (the
’010 Patent) and 6,835,743 (the ’743 Patent) (collectively,
“the Kimura patents”). The ’743 Patent is a divisional of
the same application that matured into the ’010 Patent.
BASF is the exclusive licensee of the Kimura patents in
the United States.
    After initiating suit, BASF moved the district court
for a preliminary injunction. In evaluating whether a
preliminary injunction was warranted, the district court
held a Markman hearing and preliminarily construed the
claims of the Kimura patents. BASF Agro B.V. v.
Makhteshim Agan of N. Am., Inc., No. 1:10-CV-276, 2011
WL 2135129 (M.D.N.C. May 27, 2011). In construing the
claims, the district court looked to the patents’ shared
specification and prosecution history. The district court
determined that during examination before the Patent
Office the inventor, Yasuo Kimura, had disclaimed “barri-
er treatments.” Specifically, the district court found that
Kimura had disclaimed “applying insecticide without
loopholes around a building, and applying insecticide
without loopholes under a building, respectively.” Id. at
*4. Because the district court found that the instructions
included with MANA’s accused product mentioned only
barrier treatments, the district court denied BASF’s
request for a preliminary injunction.
4                             BASF AGRO   v. MAKHTESHIM AGAN
    The district court subsequently issued a detailed
claim construction order in which it confirmed its earlier
finding that Kimura had disclaimed treatments that do
not create “untreated locations (i.e., loopholes) through
which the crawling insect can reach the building without
being exposed to the insecticide.” BASF Agro B.V. v.
Makhteshim Agan of N. Am., Inc., No. 1:10-CV-276, 2011
WL 2607940, at *6–10 (M.D.N.C. June 30, 2011). In view
of the district court’s claim construction order, MANA
moved for summary judgment of non-infringement. The
district court granted MANA’s motion and entered sum-
mary judgment of non-infringement. BASF Agro B.V. v.
Makhteshim Agan of N. Am., Inc., No. 1:10-CV-276, 2012
WL 84985 (M.D.N.C. Jan. 11, 2012).
    BASF appeals. We have jurisdiction under 35 U.S.C.
§ 1295(a)(1).
                 II. STANDARDS OF REVIEW
    “[T]he construction of a patent . . . is exclusively with-
in the province of the court.” Markman v. Westview
Instruments, Inc., 517 U.S. 370, 372 (1996). We thus
review issues of claim construction without deference.
See Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1456
(Fed. Cir. 1998) (en banc).
    We review a district court's grant of summary judg-
ment under the law of the regional circuit, in this case the
Fourth Circuit. Landmark Screens, LLC v. Morgan,
Lewis, & Bockius, LLP, 676 F.3d 1354, 1361 (Fed. Cir.
2012). The Fourth Circuit reviews a district court’s grant
of summary judgment de novo. Laber v. Harvey, 438 F.3d
404, 415 (4th Cir. 2006). Summary judgment is appropri-
ate if the pleadings, depositions, answers to interrogato-
ries, and admissions on file, together with the affidavits,
if any, show “that there is no genuine dispute as to any
material fact and the movant is entitled to judgment as a
matter of law.” Fed. R. Civ. P. 56; see also Celotex Corp. v.
Catrett, 477 U.S. 317, 324 (1986). In reviewing a district
 BASF AGRO   v. MAKHTESHIM AGAN                          5
court’s grant of summary judgment, we view the facts in
the light most favorable to the losing party. See Anderson
v. Liberty Lobby, Inc., 477 U.S. 242, 255 (1986).
                 III. THE KIMURA PATENTS
    The Kimura patents are directed to a method of ap-
plying a broad-spectrum insecticide known as Fipronil.
The goal of the patented method is to protect existing or
planned buildings against “crawling insects, especially
against termites.” ’010 Patent col. 1 ll. 6–8.
    According to the patented method, “an effective
amount of insecticide active compound is spread around
or under the said building at discrete locations.” Id. at
[57] (abstract) (emphasis added). The following illustra-
tion in the ’010 Patent shows an example of these “dis-
crete locations,” which are illustrated as opaque boxes
placed around the outline of a building’s perimeter:




Id. col. 5 ll. 27–35. According to the Kimura patents’
shared specification, the patented method provides an
advantage over prior art methods which required “opera-
tors [to] apply the chemical around or under the building
or houses to form a barrier against termites [sic] inva-
sion.” Id. col. 1 ll. 10–13. The specification explains that
the prior art methods suffered from a significant disad-
vantage: “loopholes in the treatment[s] may cause failure
of protection of the houses.” Id. col. 1 ll. 13–14. The
Kimura patents sought to alleviate this problem by
providing “a curative treatment which is effective even
when attacked parts are untreated,” that is, the patents
sought “to provide a termite treatment without barrier.”
Id. col. 1 ll. 35–37, 43–45.
6                             BASF AGRO   v. MAKHTESHIM AGAN
    According to the patented method, “the active ingredi-
ent is applied on discrete locus [sic],” id. col. 3 ll. 41–42,
“inside or outside the outline of the house or buildings to
be built,” id. col. 3 ll. 23–25. Representative claim 1 of the
’010 Patent recites a “[p]rocess for the protection of a
building against damage caused by insects,” comprising
    b) forming treated and untreated locations along
        the perimeter of the building by applying an
        effective amount of said solution or suspension
        to discrete locations around or under said
        building along the perimeter of the building,
        wherein the treated locations are the discrete
        locations along the perimeter of the building
        where said solution or suspension has been
        applied and the untreated locations are the
        remaining portions of the perimeter where the
        solution or suspension was not applied;
    wherein the combination of said treated locations
        and said untreated locations along the perim-
        eter of the building equal the total perimeter
        of the building and further wherein said
        treated locations make up 0.5 to 7.5 meter per
        10 meter of the total perimeter of the building
        ....
Id. col. 5, claim 1 (emphasis added). In accordance with
the description in the specification, the claim requires
both “treated and untreated locations along the perimeter
of the building” instead of a continuous barrier without
loopholes.
                 A. PROSECUTION HISTORY
    During prosecution of the ’010 Patent, the examiner
rejected Kimura’s claimed invention as obvious in view of
several prior art references. Although Kimura sought to
distinguish the cited prior art references, the examiner
issued a final rejection. Following the examiner’s final
 BASF AGRO   v. MAKHTESHIM AGAN                           7
rejection, Kimura filed a response including a declaration
supporting patentability made by Dr. Joe Hope (the “Hope
declaration”), whom Kimura held out as one of ordinary
skill in the art. Dr. Hope suggested that, in contrast to
Kimura’s invention, all prior art methods taught forming
a complete barrier without loopholes. In response to the
Hope declaration, the examiner allowed Kimura’s applica-
tion, which issued as the ’010 Patent on July 2, 2002.
              1. THE EXAMINER’S REJECTIONS
    The examiner initially rejected the claims of Kimura’s
patent application as obvious in view of a combination of
prior art references. These references included two U.S.
patents to Crosby and Mihealsick (U.S. Patent Nos.
3,624,953 and 5,390,440) (“Crosby” and “Mihealsick”), and
two international applications filed under the Patent
Cooperation Treaty (Int’l Pub. Nos. WO 95/22902 and WO
96/16544). The examiner found that the international
applications taught “that fipronil is an old termiticide
applied to the same locus of the claims.” The examiner
also found that the Crosby and Mihealsick patents “dis-
close methods of combating termites by applying a termit-
icide to discrete locations around a building or into the
ground around a building.”
    Kimura sought to overcome the examiner’s rejections
by distinguishing the cited references. Kimura distin-
guished the Crosby patent as being “designed to provide a
‘barrier’ around the building to be protected” rather than
forming both “treated and untreated locations” as in
Kimura’s claimed invention:
   [T]he method disclosed in the Crosby patent is de-
   signed to provide a "barrier" around the building
   to be protected. There is no teaching or suggestion
   in the Crosby patent of a method for the protec-
   tion of a building wherein a dilute solution or sus-
   pension of an insecticide in a liquid is applied to
8                            BASF AGRO   v. MAKHTESHIM AGAN
    discrete locations along the perimeter of the build-
    ing so as to form treated and untreated locations.
(emphasis added). Kimura similarly distinguished the
Mihealsick patent as requiring “the formation of a barrier
that has no untreated locations”:
    There is no teaching or suggestion whatsoever of a
    process for the protection of a building wherein a
    dilute solution or suspension of an insecticide is
    applied to discrete locations along the perimeter of
    the building to form treated and untreated loca-
    tions. In contrast, the purpose of Mihealsick appa-
    ratus and method is to ensure the formation of a
    barrier that has no untreated locations.
    Kimura insisted that the prior art did not contain any
“teachings or suggestions that would motivate an artisan
of ordinary skill to deviate from the established practice of
creating a continuous barrier around a building.” Kimura
argued that none of the cited references “teaches the
deliberate creation of untreated locations (i.e., loopholes)
through which the crawling insect can reach the building
without being exposed to the insecticide.” “In fact,” Ki-
mura urged, “all of the cited documents teach away from
this approach because they endeavor to create a barrier
between the crawling insects and the building so that the
insect cannot reach the building without being exposed to
the insecticide.”
    The Examiner was not persuaded by Kimura’s argu-
ments, and in a final Office action rejected Kimura’s
claims as obvious in view of the cited prior art references.
The Examiner noted,
    The prior art teaches that the same composition
    may be applied to the same locus in the same
    amounts. Therefore, the results would clearly be
    the same. The above rejection is deemed proper
    and adhered to.
 BASF AGRO   v. MAKHTESHIM AGAN                            9
                2. THE HOPE DECLARATION
     In response to the examiner’s final rejection, Kimura
filed an amendment to the claims and submitted a decla-
ration by Dr. Joe Hope. Kimura represented Dr. Hope as
an “artisan who is clearly skilled in this field.” Kimura’s
remarks argued that “Dr. Hope verifies that . . . a skilled
artisan would not have attempted to protect a structure
against [termites] . . . by applying an insecticidally active
substance to discrete locations around the perimeter of
the structure so as to form treated and untreated loca-
tions around the perimeter of the structure in the manner
claimed.” Remarks 9–10. Kimura also argued that “Dr.
Hope also verifies that the cited prior art is all directed to
so called ‘barrier’ treatment techniques, wherein a com-
plete barrier is formed around the perimeter of a structure
to be protected.” Remarks 10.
     In his declaration, Dr. Hope stated that “the teaching
of the common general knowledge and prior art . . . directs
the skilled artisan to make a barrier treatment of chemi-
cal insecticide around a structure.” Dr. Hope individually
distinguished the prior art references cited by the exam-
iner. The Crosby patent, he said, “recites a method
wherein a volatile insecticide is placed at discrete loca-
tions around a house with the intention that the insecti-
cide may vaporize and thus create a barrier to termite
ingress.” The Mihealsick reference, Dr. Hope said, in-
volves the application of insecticide “under a concrete slab
and/or around a house” for the purpose of “creating or
regenerating a barrier.” Dr. Hope characterized Kimura’s
claimed invention as an “unobvious and surprising pro-
cess” because “insecticide is applied to discrete locations
along the perimeter of the structure to form treated and
untreated locations along the perimeter.”
   Based on Dr. Hope’s declaration and Kimura’s re-
marks, the examiner allowed the claims of Kimura’s
application.
10                           BASF AGRO   v. MAKHTESHIM AGAN
                IV. THE ACCUSED PRODUCTS
    MANA sells an insecticidal compound containing
Fiprionil under the trade name “Taurus SC.” MANA’s
Taurus SC product includes a label with information and
application instructions. The relevant labeling provides
that the product, “when used as recommended in this
label, provides effective prevention and/or control of
subterranean termites.” MANA’s labeling further pro-
vides that the product “should be applied in a manner to
provide a continuous treated zone.”
    The portion of MANA’s labeling relevant to this suit
describes “Exterior Perimeter/Localized Interior (EP/LI)
Structural Termite Treatment.” According to the instruc-
tions for this “EP/LI” treatment,
     Structural termite protection is achieved by first
     establishing a continuous treated zone along the
     exterior foundation of the structure. Localized in-
     terior treatments are then made to areas where
     known termite activity is observed. . . .
     This treatment method is designed to be non-
     invasive to the interior of the structure by apply-
     ing a continuous treatment along the exterior
     foundation and only treating the interior areas
     that show termite activity.
With respect to the exterior perimeter aspect of the EP/LI
treatment, the instructions provide, “When conducting an
exterior perimeter application, [the product] must be
applied in a manner to provide a continuous treatment
zone to prevent termites from infesting the structure.” As
the district court noted, the instructions repeatedly call
for a “continuous treated zone” along the exterior of the
structure, or a “complete exterior perimeter treatment
zone.”
    While the EP/LI instructions call for a continuous
treated zone along the exterior perimeter of a structure,
 BASF AGRO   v. MAKHTESHIM AGAN                         11
they specify that a “continuous treated zone” is unneces-
sary on the structure’s interior. Instead, “[t]argeted
interior applications may be made to vulnerable areas . . .
as part of a complete treatment.” These targeted interior
applications include “treating the interior areas that show
termite activity.”
    BASF accuses MANA of infringing the Kimura pa-
tents by virtue of the localized interior (“LI”) portion of
the instructions on its product labels.
        V. CLAIM CONSTRUCTION AND DISCLAIMER
    The district court construed the claims of the Kimura
patents based on a detailed review of the patents’ shared
specification and prosecution history. The district court
focused in particular on Kimura’s representations to the
Patent Office during examination, including the Hope
declaration. Based in part on Kimura’s representations,
the district court determined that Kimura had “dis-
claimed applying insecticide without loopholes around a
building, and applying insecticide without loopholes
under a building, respectively.” BASF, 2011 WL 2607940,
at *7.
    The district court rejected BASF’s attempts to qualify
various statements in the Hope declaration and to intro-
duce extrinsic evidence, in the form of expert testimony,
that Kimura’s disclaimer was not intended to be so broad.
Id. at *10. The district court concluded that the claimed
method, properly construed, “(a) requires the deliberate
creation of untreated locations (i.e., loopholes) through
which the crawling insect can reach the building without
being exposed to the insecticide and (b) disclaims applying
insecticide without loopholes around a [future] building,
under a [future] building, and both around a [future]
building and under a [future] building.” Id. at *11.
    On appeal, BASF argues that the district court con-
strued Kimura’s disclaimer too broadly. BASF concedes
12                          BASF AGRO   v. MAKHTESHIM AGAN
that the Kimura patents teach a treatment “without
barrier.” Nevertheless, BASF argues that the district
court should have limited the disclaimed treatments to
treatments “without loopholes both around and under a
building.” According to BASF, the specification of the
Kimura patents and the Hope declaration support its
proposed construction. BASF argues further that the
extrinsic evidence of record, including expert testimony,
confirms that barrier treatments were understood as
blocking all points of entry, both inside and outside a
building’s boundary. Finally, BASF argues that the
claims of the Kimura patents use the open-ended term
“comprising.” In BASF’s view, this open-ended term
warrants a finding of infringement even where the ac-
cused product combines a localized interior treatment
with an exterior barrier treatment. BASF asks us to
reverse the district court’s claim construction and sum-
mary judgment of non-infringement.
    Determining the proper meaning of a claim begins
with the language of the claim. See Phillips v. AWH
Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en banc)
(“[T]he claims are of primary importance, in the effort to
ascertain precisely what it is that is patented.”). We
presume that the terms in the claim mean what they say.
Tate Access Floors, Inc. v. Interface Architectural Res.,
Inc., 279 F.3d 1357, 1370 (Fed. Cir. 2002). We interpret
the claim’s words “in light of the intrinsic evidence of
record, including the written description, the drawings,
and the prosecution history.” Teleflex, Inc. v. Ficosa N.
Am. Corp., 299 F.3d 1313, 1324 (Fed. Cir. 2002). If a
claim term has a plain and ordinary meaning, our inquiry
ends. Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576,
1582 (Fed. Cir. 1996). If, however, the claim term does
not have an ordinary meaning, and its meaning is not
clear from a plain reading of the claim, “we turn to the
remaining intrinsic evidence, including the written de-
scription, to aid in our construction of that term.” Telem-
 BASF AGRO   v. MAKHTESHIM AGAN                         13
ac Cellular Corp. v. Topp Telecom, Inc., 247 F.3d 1316,
1326 (Fed. Cir. 2001).
    We have held that “the specification is always highly
relevant to the claim construction analysis. Usually, it is
dispositive; it is the single best guide to the meaning of a
disputed term.” Vitronics, 90 F.3d at 1582. The construc-
tion that stays true to the claim language and most
naturally aligns with the patent’s description of the
invention will be, in the end, the correct construction.
Renishaw PLC v. Marposs Societa' per Azioni, 158 F.3d
1243, 1250 (Fed. Cir. 1998) (“Ultimately, the interpreta-
tion to be given a term can only be determined and con-
firmed with a full understanding of what the inventors
actually invented and intended to envelop with the
claim.”).
     During the process of obtaining a patent, a patentee
may make statements to the Patent Office to distinguish
her claimed invention from the prior art. Where such
statements indicate a clear disavowal of subject matter,
the patentee disclaims such subject matter and narrows
the scope of her claims. Ekchian v. Home Depot, Inc., 104
F.3d 1299, 1304 (Fed. Cir. 1997) (“[S]ince, by distinguish-
ing the claimed invention over the prior art, an applicant
is indicating what the claims do not cover, he is by impli-
cation surrendering such protection.”). The public has a
right to rely on representations a patentee has made in
the course of obtaining her patent. See Spectrum Int'l,
Inc. v. Sterilite Corp., 164 F.3d 1372, 1378-79 (Fed. Cir.
1998); Digital Biometrics, Inc. v. Identix, Inc., 149 F.3d
1335, 1347 (Fed. Cir. 1998); Southwall Techs. Inc. v.
Cardinal IG Co., 54 F.3d 1570, 1576 (Fed. Cir. 1995)
(“The prosecution history limits the interpretation of
claim terms so as to exclude any interpretation that was
disclaimed during prosecution.”); Standard Oil Co. v.
American Cyanamid Co., 774 F.2d 448, 452 (Fed. Cir.
1985) (stating that the prosecution history, which in-
cludes “all express representations made by or on behalf
14                           BASF AGRO   v. MAKHTESHIM AGAN
of the applicant to the examiner to induce a patent grant,”
limits the interpretation of the claims “so as to exclude
any interpretation that may have been disclaimed or
disavowed during prosecution in order to obtain claim
allowance”); see also Warner-Jenkinson Co., Inc. v. Hilton
Davis Chem. Co., 520 U.S. 17, 30 (1997) (noting “the
public’s right to clear notice of the scope of the patent as
embodied in the patent file.”).
    Generally, a patent’s intrinsic record does not warrant
consideration of extrinsic evidence. Where a patent’s
claims, written description, and prosecution history are
complete and unambiguous, a court need not resort to
extrinsic evidence such as treatises, technical references,
or expert testimony. Where the intrinsic record leaves
ambiguities and unresolved questions, however, a court
may consider extrinsic evidence, including expert testi-
mony. Phillips, 415 F.3d at 1317–18; Lighting World, Inc.
v. Birchwood Lighting, Inc., 382 F.3d 1354, 1359 (Fed.
Cir. 2004). Extrinsic evidence must be “given the appro-
priate weight by the trial court.” Amkor Tech., Inc. v. Int'l
Trade Comm’n, 692 F.3d 1250, 1259-60 (Fed. Cir. 2012)
(quoting Spansion Inc. v. Int'l Trade Comm’n, 629 F.3d
1331, 1344 (Fed. Cir. 2010)). To this end, we have been
careful to distinguish between, on one hand, expert testi-
mony on the state of the art, and on the other hand,
expert testimony regarding the proper construction of a
disputed claim term. See, e.g., Vitronics, 90 F.3d at 1585.
The latter should play a more limited role in a court’s
analysis, especially where the intrinsic record is self-
evident.
    In any event, extrinsic evidence cannot vary the terms
of the claims or otherwise contradict the intrinsic record.
Markman v. Westview Instruments, Inc., 52 F.3d 967, 981
(Fed. Cir. 1995), aff’d, 517 U.S. 370 (1996). Accordingly,
expert testimony inconsistent with the intrinsic record
has little if any probative value. Vitronics, 90 F.3d at
1584–85. (“[E]ven if the judge permissibly decided to hear
 BASF AGRO   v. MAKHTESHIM AGAN                         15
all the possible evidence before construing the claim, the
expert testimony, which was inconsistent with the specifi-
cation and file history, should have been accorded no
weight.”).
    We find here that the district court correctly con-
strued the claims of the Kimura patents based on its
determination that Kimura had disclaimed “barrier
treatments” without loopholes. First, the language of the
claims suggests exclusion of barrier treatments. Second,
the specification clarifies and confirms a disclaimer.
Third, Kimura relied on the disclaimer during prosecu-
tion. Fourth, the claims’ open-ended language does not
moot Kimura’s disclaimer. And fifth, extrinsic evidence is
not available to contradict such a clear and definite disa-
vowal of subject matter.
    First, the language of the claims suggests exclusion of
barrier treatments. The claims unambiguously require
areas that are treated and untreated: “forming treated
and untreated locations . . . by applying an effective
amount . . . to discrete locations around or under said
building.” The claims specify that “the untreated loca-
tions are the remaining portions of the perimeter where
the solution or suspension was not applied.” In accord-
ance with this language, the claims require portions of the
perimeter to which insecticide has not been applied. In
other words, the perimeter must have untreated “loop-
holes.” Thus, the claims exclude treatments that form a
single unbroken barrier, or a barrier without such loop-
holes.
    Second, the shared specification of the Kimura pa-
tents disclaims barrier treatments. According to the
specification the patented method provides an advantage
over prior art methods which required “operators [to]
apply the chemical around or under the building or hous-
es to form a barrier against termites [sic] invasion.” A
disadvantage of these prior art methods, the specification
16                           BASF AGRO   v. MAKHTESHIM AGAN
explains, is that “loopholes in the treatment may cause
failure of protection of the houses.” Thus, “an object of the
instant invention is to provide a curative treatment which
is effective even when attacked parts are untreated,” that
is “to provide a termite treatment without barrier.” ’010
Patent col. 1 ll. 35–37, 43–45. According to the patented
method, “the active ingredient is applied on discrete locus
[sic],” id. at col. 3 ll. 41–42, not continuously to form a
barrier free of loopholes. The specification thus confirms
that the claims do not cover the prior art’s loophole-free
barrier treatments.
    Third, the prosecution history indicates a clear dis-
claimer of barrier treatments. Kimura distinguished the
Crosby and Mihealsick patents cited by the examiner as
being “designed to provide a ‘barrier’ around the building
to be protected” rather than forming both “treated and
untreated locations” as in the claimed invention. Those
patents, Kimura said, require “the formation of a barrier
that has no untreated locations.” Kimura insisted that
the prior art did not contain any “teachings or suggestions
that would motivate an artisan of ordinary skill to deviate
from the established practice of creating a continuous
barrier around a building.”
    Kimura asked the examiner to allow the claims based
on Kimura’s suggestion that no prior art reference “teach-
es the deliberate creation of untreated locations (i.e.,
loopholes) through which the crawling insect can reach
the building without being exposed to the insecticide.”
Kimura said, “all of the cited documents teach away from
this approach because they endeavor to create a barrier
between the crawling insects and the building so that the
insect cannot reach the building without being exposed to
the insecticide.” Thus, Kimura intended to disclaim all
treatments that form a barrier to prevent insects from
breaching a building’s perimeter without exposure to
insecticide.
 BASF AGRO   v. MAKHTESHIM AGAN                         17
     Kimura further relied during prosecution on the dec-
laration of Dr. Joe Hope, who asserted that “the teaching
of the common general knowledge and prior art as of [the
filing of Kimura’s application] directs the skilled artisan
to make a barrier treatment of chemical insecticide
around a structure . . . i.e., [having] no untreated loca-
tions.” Hope Decl. 2. Dr. Hope distinguished the method
of the Crosby patent, which teaches “discrete applications
around a house,” as nevertheless being designed to “create
a barrier to termite ingress.” Id. at 3. Finally, Dr. Hope
distinguished the Mihealsick patent as teaching a method
of applying insecticide “under a concrete slab and/or
around a house” for the purpose of “creating or regenerat-
ing a barrier to termites.” Id. After reviewing the exam-
iner’s cited prior art, Dr. Hope concluded that Kimura’s
method was “unobvious and surprising.” Id. at 3–4.
    It is evident from Dr. Hope’s declaration that he con-
sidered Kimura’s method “surprising” because it did not
require the creation of barriers around the perimeter of a
building. Based on Dr. Hope’s analysis of the prior art
and characterization of the claimed invention, the exam-
iner allowed the claims of Kimura’s application. On
issuance, Dr. Hope’s representations became part of the
Kimura patents’ intrinsic record, and the public is enti-
tled to rely on Dr. Hope’s representations in determining
the claimed invention’s scope.
    Fourth, the claims’ use of the open-ended term “com-
prising” is not sufficient to overcome Kimura’s clear
disavowal of certain subject matter. As we have said,
“The open-ended transition ‘comprising’ does not free the
claim from its own limitations.” Kustom Signals, Inc. v.
Applied Concepts, Inc., 264 F.3d 1326, 1332 (Fed. Cir.
2001). Nor is “comprising” a talismanic incantation that
counteracts a clear disclaimer. Spectrum, 164 F.3d at
1379–80 (“‘Comprising’ is not a weasel word with which to
abrogate claim limitations . . . [or] restore [] excluded
subject matter.”). We find Kimura’s use of the word
18                            BASF AGRO   v. MAKHTESHIM AGAN
“comprising” insufficient to overcome the clear and defi-
nite disclaimer which is evident from the Kimura patents’
text and prosecution history.
     Fifth, the expert testimony offered by BASF regarding
the state of the prior art is insufficient to change the scope
of Kimura’s disclaimer. Extrinsic evidence cannot vary
the terms of the claims or otherwise contradict the intrin-
sic record. Markman, 52 F.3d at 981. Even testimony
from a qualified expert has little probative value if it is
inconsistent with the intrinsic record. Vitronics, 90 F.3d
at 1584 (“[E]ven if the judge permissibly decided to hear
all the possible evidence before construing the claim, the
expert testimony, which was inconsistent with the specifi-
cation and file history, should have been accorded no
weight.”). BASF presented testimony that at the time of
Kimura’s invention an ordinarily skilled artisan would
have understood barrier treatments to require formation
of a complete barrier both around a building and under-
neath its foundation.
    Kimura’s argument that the prior art required treat-
ment both around and under a building is contrary to the
evidence intrinsic to Kimura’s patents. The specification
of the patents suggests that the prior art did not require
dual application both around and under a building. ’010
Patent col. 1 ll. 10–13 (referring to prior art methods in
which “operators apply the chemical around or under the
building or houses to form a barrier.”). Indeed, the prior
art references cited by the examiner teach barrier treat-
ments applied around but not under a building. See
Crosby fig.1; Mihealsick fig.2. Moreover, Kimura’s and
Dr. Hope’s representations to the Patent Office indicate a
clear disclaimer of treatments that form a barrier either
around or under a building. Kimura Resp. 11 (distin-
guishing the Crosby patent on the basis that “the method
disclosed in the Crosby patent is designed to provide a
‘barrier’ around the building to be protected.” (emphasis
added)); Hope Decl. 2 (distinguishing the Mihealsick
 BASF AGRO   v. MAKHTESHIM AGAN                         19
patent as teaching insecticide application “under a con-
crete slab and/or around a house” (emphasis added)).
    For the reasons above, we conclude that the district
court correctly construed the claims of the Kimura pa-
tents to exclude treatments which require application of
insecticide “without loopholes around a building, under a
building, and both around a building and under a build-
ing.”
                    VI. INFRINGEMENT
    Where, in the course of prosecuting her patent, a pa-
tentee relinquishes certain subject matter, she may not
“during subsequent litigation escape reliance [by another
party] upon this unambiguous surrender of subject mat-
ter.” 1 Southwall, 54 F.3d at 1581. Quite simply, “[c]laims
may not be construed one way in order to obtain their
allowance and in a different way against accused infring-
ers.” Id. at 1576; see also Alpex Computer Corp. v. Nin-
tendo Co., 102 F.3d 1214, 1221 (Fed. Cir. 1996)
(“[B]ecause Alpex admitted during prosecution that its
claims do not cover a video display system based on shift
registers as in Okuda . . . Alpex’s claims cannot now be
construed to cover the [accused device], which possesses
the same structural and functional traits as Okuda.”);
Spectrum, 164 F.3d at 1378-79.
    The parties do not dispute that the label of the ac-
cused products teaches an EP/LI treatment method in

   1    This principle applies with equal force to argu-
ments made by a patentee in reexamination or post-grant
review. See, e.g., Cole v. Kimberly-Clark Corp., 102 F.3d
524, 532 (Fed. Cir. 1996) (“We also believe the district
court correctly interpreted the prosecution history to
require that the ‘perforation means’ limitation cannot be
construed to include ultrasonic bonded seams. Cole
surrendered ultrasonic bonded seams in her requests for
reexamination.”).
20                          BASF AGRO   v. MAKHTESHIM AGAN
which an operator applies insecticide around a building to
form a barrier, but inside the building only at discrete
locations. Because MANA’s accused product instructs
application of a complete barrier around a building, it
falls within the scope of Kimura’s disclaimer. BASF may
not now attempt to recapture disclaimed subject matter
by isolating and selecting individual components of the
accused method, which as a whole reaches the very result
that Kimura expressly disclaimed.
                    VII. CONCLUSION
    Because Kimura expressly disclaimed insecticide
treatments that form a complete barrier around or under
a building, and because MANA’s accused product require
a complete barrier around a building, MANA’s product
cannot infringe the Kimura patents. The district court
properly granted MANA’s motion for summary judgment
of non-infringement. The final judgment of the district
court is
                      AFFIRMED.
