Laboratory Corporation of America Holdings, Labcorp Genetics, Inc., the General… v. Qiagen Sciences, LLC, Qiagen LLC, Fka Qiagen, Inc., Qiagen Beverly, LLC, Fka Qiagen…

United States Court of Appeals
for the Federal Circuit
______________________
LABORATORY CORPORATION OF AMERICA
HOLDINGS, LABCORP GENETICS, INC., THE
GENERAL HOSPITAL CORPORATION, DBA
MASSACHUSETTS GENERAL HOSPITAL,
Plaintiffs-Appellees
v.
QIAGEN SCIENCES, LLC, QIAGEN LLC, FKA
QIAGEN, INC., QIAGEN BEVERLY, LLC, FKA
QIAGEN BEVERLY, INC., QIAGEN
GAITHERSBURG, LLC, FKA QIAGEN
GAITHERSBURG, INC., QIAGEN GMBH, QIAGEN
N.V., JONATHAN ARNOLD,
Defendants-Appellants
______________________
2023-2350
______________________
Appeal from the United States District Court for the
District of Delaware in No. 1:18-cv-01019-MN, Judge
Maryellen Noreika.
______________________
Decided: August 13, 2025
______________________
EDWARD R. REINES , Jones Day, Palo Alto, CA, argued
for plaintiffs-appellees. Also represented by ALEXANDER
HORNAT , L EIGH J OHN MARTINSON, WYLEY S AYRE P ROCTOR ,
McCarter & English, LLP, Boston, MA; D ANIEL M. SILVER ,
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LABORATORY CORPORATION OF AMERICA HOLDINGS v.
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2
Wilmington, DE.
D AVID L EON BILSKER, Quinn Emanuel Urquhart & Sul-
livan, LLP, San Francisco, CA, argued for defendants-ap-
pellants. Also represented by ANDREW EDWARD N ARAVAGE ;
BRIAN C. CANNON, Redwood Shores, CA.
______________________
Before L OURIE, D YK, and CUNNINGHAM , Circuit Judges.
L OURIE, Circuit Judge.
Qiagen Sciences, LLC and others1 (collectively “Qi-
agen”) appeal from a final judgment of the United States
District Court for the District of Delaware following a jury
trial. The jury awarded Laboratory Corporation of Amer-
ica Holdings, Labcorp Genetics, Inc., and The General Hos-
pital Corporation (collectively, “Appellees”)2 damages for
infringement of its U.S. Patent 10,017,810 (“the ’810 pa-
tent”) and U.S. Patent 10,450,597 (“the ’597 patent”). See
J.A. 73–77. After trial, the district court denied Qiagen’s
renewed motion for judgment as a matter of law.
ArcherDX, LLC v. Qiagen Scis., LLC, No. 18-cv-1019,
1 The other Defendant-Appellants include Qiagen
LLC, fka Qiagen, Inc., Qiagen Beverly, LLC fka Qiagen
Beverly, Inc., Qiagen Gaithersburg, LLC, fka Qiagen
Gaithersburg, Inc., Qiagen GmbH, Qiagen N.V., and Jona-
than Arnold.
2 On August 30, 2024, ArcherDX, LLC (“Archer”)
and The General Hospital Corporation, the original plain-
tiffs, moved unopposed to substitute Laboratory Corpora-
tion of America Holdings and Labcorp Genetics, Inc. in
place of Archer, noting that while the case was on appeal,
Labcorp purchased Archer’s interest in the patents in suit
and relevant license. ECF No. 45. We granted that motion.
ECF No. 49.
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2022 WL 4597877 (D. Del. Sep. 30, 2022) (“Decision”). Qi-
agen timely appealed and, as explained below, we reverse.
BACKGROUND
I
Appellees’ ’810 and ’597 patents share largely overlap-
ping specifications and are generally directed to methods
of preparing DNA samples for sequencing. Because se-
quencing an entire genome is traditionally expensive and
time consuming, researchers developed “enrichment” tech-
niques. Enriching a sample refers to the process of produc-
ing copies of the region of interest, as opposed to the entire
genome, to make sequencing more efficient. The region of
interest, also referred to as the “target area,” is often the
part of a DNA fragment that a researcher is interested in
studying. The target area, for example, may be a section
that includes a mutation, or alteration in genetic infor-
mation, that can lead to disease. Both patents recognize
the benefits of target enrichment prior to sequencing. See
’810 patent col. 1 ll. 38–40 (“Target enrichment prior to
next-generation sequencing is more cost-effective than
whole genome . . . sequencing[.]”); ’597 patent col. 1 ll. 26–
28 (same).
Enrichment methods typically rely on the polymerase
chain reaction (“PCR”) to amplify (make copies of) a target
area in the DNA fragments contained in a DNA sample.
See generally Roche Molecular Sys., Inc. v. CEPHEID,
905 F.3d 1363, 1366 (Fed. Cir. 2018) (describing PCR); see
also ’810 patent col. 13 l. 20–col. 14 l. 60. To copy the target
area of the DNA sample, short pieces of DNA known as
“target-specific primers” mark where replication should
begin on each denatured DNA strand and serve as the
binding site for the polymerase enzyme that performs the
replication. See id.; see also ’810 patent col. 77 l. 19–col. 78
l. 16, col. 15 ll. 58–61, col. 16 ll. 33–39, 53–57. By designing
target-specific primers so that they anneal to and start the
copying between certain sequence locations in the DNA,
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researchers can isolate and enrich the regions of sequence
that they are interested in analyzing. See Roche,
905 F.3d at 1366; ’810 patent col. 18 ll. 24–29. Meanwhile,
other types of “primers” assist with different functions dur-
ing the DNA sequencing preparation process. “Adaptor
primers” may be designed against the adaptors, which are
artificial sequences of DNA ligated to the DNA fragments
in the DNA sample, to assist in amplifying only fragments
that have ligated adapters. ’810 patent col. 16 l. 64–col. 17
l. 8; J.A. 579. “Sequencing primers” enable the library of
enriched DNA fragments to be read by the sequencing in-
strument. ’810 patent col. 3 ll. 30–33. The issues in this
case involve the design and operation of different types of
primers and how they assist in preparing DNA samples for
sequencing and analysis.
The claimed method of the ’810 patent generally re-
quires first ligating (attaching) an adaptor (a known artifi-
cial sequence) to each fragmented piece of DNA, and then
conducting two rounds of amplification with two separate
pairs of primers: a first adaptor primer and first target-
specific primer, and a second adaptor primer and second
target-specific primer, each of which has specific defini-
tions in the patent. See ’810 patent col. 77 l. 19–col. 78 l.
16; see also id. at col. 15 ll. 58–61, col. 16 ll. 33–39, col. 16
l. 64–col. 17 l. 8 (defining the terms).
At issue in this appeal are independent claim 16 of the
’810 patent and its dependent claims 17 and 19. Exem-
plary claim 16 recites:
16. A method for preparing a nucleic acid for se-
quencing, the method comprising:
(i) ligating a universal oligonucleotide tail adaptor
that comprises a first ligatable duplex end and a
second unpaired end to a nucleic acid comprising a
known target nucleotide sequence to produce a liga-
tion product, the universal oligonucleotide tail
adaptor comprising an amplification strand and a
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blocking strand, wherein a 3′ duplex portion of the
amplification strand and a 5′ duplex portion of the
blocking strand are substantially complementary
and form the first ligatable duplex end;
(ii) amplifying the ligation product using a first tar-
get-specific primer that specifically anneals to the
known target nucleotide sequence and a first adap-
tor primer having a nucleotide sequence identical
to a first portion of the amplification strand; and
(iii) amplifying an amplification product of (ii) us-
ing a second target-specific primer that specifically
anneals to the amplification product of (ii) and a
second adaptor primer having a nucleotide se-
quence identical to a second portion of the amplifi-
cation strand, wherein ligating in step (i) comprises
performing an overhang ligation reaction, and
wherein the universal oligonucleotide tail adaptor
further comprises a barcode portion.
’810 patent col. 77 l. 19–col. 78 l. 16 (emphases added). Rel-
evant here, the district court construed the term “second
target-specific primer” to mean “a single-stranded oligonu-
cleotide comprising a 3′ portion comprising a nucleic acid
sequence that can specifically anneal to a portion of the
known target nucleotide sequence comprised by the am-
plicon resulting from step (b), and a 5′ portion comprising
a nucleic acid sequence that is identical to a second se-
quencing primer.” See ArcherDx, Inc. v. QIAGEN Scis.,
LLC, No. 18-cv-1019, 2019 WL 6785546, at *1 (D. Del. Dec.
12, 2019) (“’810 Patent Claim Construction Order”) (em-
phases added). The court also construed the term “second
adaptor primer” to mean “a nucleic acid molecule compris-
ing a nucleic acid sequence identical to a portion of the first
sequencing primer and is nested with respect to the first
adaptor primer.” Id. (emphasis added).
The district court further construed the term “known
target nucleotide sequence,” which appears in the
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construction of “second target-specific primer,” as “a por-
tion of a target nucleic acid for which the sequence (e.g. the
identity and order of the nucleotide bases comprising the
nucleic acid) is known.” Id. Later, the district court clari-
fied that the term “portion of the known target nucleotide
sequence,” which also appears in the definition of “second
target-specific primer,” must be “a portion of the same
known target nucleotide sequence that is referenced in step
(i) of claim 16.” See J.A. 808–09 (revisiting claim construc-
tion of “second target-specific primer”).
The ’597 patent is said to be an improvement over the
earlier ’810 patent. See J.A. 512–13; see also Appellee
Br. 8. Instead of adding adaptors to both ends of the DNA
fragments as in the ’810 patent, the ’597 method generally
uses several random primers in their place. Thus, unlike
the ’810 patent, which uses PCR primers for known se-
quences on both ends of a DNA fragment, the ’597 patent
uses a target-specific primer on one end and random pri-
mers on the other.
At issue in this appeal are independent claim 1 of the
’597 patent and its dependent claims 5 and 19. Exemplary
claim 1 recites:
1. A method of preparing nucleic acids for analy-
sis, the method comprising:
(a) contacting a first nucleic acid template compris-
ing a sequence of a first strand of a double-stranded
target nucleic acid with a complementary target-
specific primer that comprises a target-specific hy-
bridization sequence, under conditions to promote
template-specific hybridization and extension of
the target-specific primer;
(b) contacting a second nucleic acid template com-
prising a sequence of a second strand that is com-
plementary to the sequence of the first strand of
the double-stranded target nucleic acid with a
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plurality of different primers that share a common
sequence that is 5′ to different hybridization se-
quences, under conditions to promote template-
specific hybridization and extension of at least one
of the plurality of different primers, wherein the
different hybridization sequences have different 3′
ends, and wherein each primer of the plurality of
different primers does not anneal to the same se-
quence of the double-stranded target nucleic acid
as any other primer of the plurality of different pri-
mers,
wherein, following (a) and (b), an extension product
is generated to contain both a sequence that is
characteristic of the target-specific primer and a
sequence that is characteristic of the at least one of
the plurality of different primers; and
(c) subjecting the extension product to an amplifi-
cation reaction comprising successive rounds of
polymerase extension of i) a tail primer that com-
prises a 3′ sequence that specifically anneals to the
complement of the common sequence and that com-
prises a 5′ tail sequence, and ii) a primer that spe-
cifically anneals to the complement of the
target-specific hybridization sequence.
’597 patent col. 77 ll. 12–48 (emphasis added). Relevant
here, the district court construed the term “target-specific
primer” to mean “a primer that has a level of complemen-
tarity between the primer and the target such that . . . the
primer will anneal to and mediate amplification of the tar-
get nucleic acid and will not anneal to or mediate amplifi-
cation of non-target sequences present in a sample.”
ArcherDX, Inc. v. QIAGEN Scis., LLC, No. 18-cv-1019,
2020 WL 3316055, at *1 (D. Del. June 18, 2020) (“’597 Pa-
tent Claim Construction Order”) (emphases added).
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II
On July 10, 2018, Appellees sued Qiagen, alleging that
Qiagen infringed the ’810 patent. Decision, at *1. Later,
after the ’597 patent had issued, Appellees filed an
amended complaint, adding a claim for infringement of the
’597 patent. Id. Specifically, Appellees alleged that vari-
ous Qiagen kits, containing materials used to prepare a
DNA sample for sequencing, infringe the asserted patents.
Id. To use those kits, a user first obtains and fragments a
DNA sample. Then, according to Qiagen, identical artifi-
cial sequences (adaptors) are ligated to the ends of each
DNA fragment. Those adaptors, Qiagen explains, are com-
mon to all Qiagen accused kits and contain sequences that
enable the DNA to attach to, and be sequenced by, a se-
quencing machine. Qiagen further explains that its ac-
cused kits contain three types of primers that are used in
its DNA preparation process. Forward (“FP”) and univer-
sal (“UP”) primers are designed to anneal to the comple-
ment of the adaptor sequence; a gene specific primer
(“GSP”) is designed to anneal to a sequence in the gene that
one seeks to analyze; and a sample index primer (“SIP”)
anneals to a sequence that the GSP adds on by way of a
tail.
After a five-day trial held in August 2021, the jury
found that Qiagen willfully infringed claims 16, 17, and 19
of the ’810 patent under the doctrine of equivalents and
willfully and literally infringed claims 1, 5, and 19 of the
’597 patent. Id. at *1–2. The jury also found that Appellees
failed to establish that any one of those claims was invalid.
Id. at *2. The jury awarded Appellees roughly $4.7 million
in damages. Id. Following trial, Qiagen renewed its mo-
tion for judgment as a matter of law (“JMOL”) on the jury’s
findings of infringement, no invalidity, and damages, and,
in the alternative, moved for a new trial. Id. The court
denied those motions. See id. at *3–13. Qiagen timely ap-
pealed, and we have jurisdiction under 28 U.S.C.
§ 1295(a)(1).
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D ISCUSSION
Qiagen argues that the district court erred by not
granting its renewed motion for JMOL of non-infringement
of both patents, invalidity of the ’810 patent, and no dam-
ages for both patents. For the following reasons, we re-
verse the district court’s denial of JMOL of non-
infringement of both patents because insufficient evidence
supported the jury’s findings. We therefore need not reach
the validity and damages issues.3
We review a district court’s JMOL decision under the
law of the regional circuit. Steuben Foods, Inc. v. Shibuya
Hoppmann Corp., 127 F.4th 348, 353 (Fed. Cir. 2025). The
Third Circuit reviews a JMOL decision de novo, applying
the same standard as the district court. Id. “Such a motion
should be granted only if, viewing the evidence in the light
most favorable to the nonmovant and giving it the ad-
vantage of every fair and reasonable inference, there is in-
sufficient evidence from which a jury reasonably could find
liability.” Id. (citation omitted).
Infringement is a question of fact that we review for
substantial evidence when tried to a jury. Syngenta Crop
Prot., LLC v. Willowood, LLC, 944 F.3d 1344, 1355 (Fed.
Cir. 2019). “A factual finding is supported by substantial
evidence if a reasonable jury could have found in favor of
the prevailing party in light of the evidence presented at
trial.” Provisur Techs., Inc. v. Weber, Inc., 119 F.4th 948,
952–53 (Fed. Cir. 2024), cert. denied, 145 S. Ct. 1181 (2025)
(citation omitted). We review claim construction
3 Qiagen’s invalidity argument for the ’810 patent is
contingent on the court affirming the district court’s denial
of JMOL of non-infringement. See Appellant Br. 5; 39. Be-
cause we reverse the district court’s denial of JMOL of non-
infringement, we need not reach Qiagen’s invalidity argu-
ment.
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determinations based on intrinsic evidence de novo, but,
when extrinsic evidence is considered, we review any sub-
sidiary factual findings for clear error. TomTom, Inc. v.
Adolph, 790 F.3d 1315, 1322 (Fed. Cir. 2015).
I
We begin with the ’810 patent. The jury found that Qi-
agen’s accused kits infringe claims 16, 17, and 19 under the
doctrine of equivalents. Decision, at *5. Qiagen raises two
arguments on appeal. First, it contends that it was error
to “[a]llow[] the jury to apply ‘plain meaning’ to conclude
that one sequence being identical to another, had the exact
same meaning as the one sequence being identical to a por-
tion of the other sequence.” Appellant Br. 31 (emphases
added). Specifically, it argues that the accused “second tar-
get-specific primer,” i.e., Qiagen’s SIP, is not “identical” to
the claimed “second sequencing primer,” i.e., Qiagen’s
Read2 primer, simply because they share an overlapping
“portion” of a sequence. See id. at 28–31. Second, Qiagen
argues that its accused SIP cannot be a “second target-spe-
cific primer” under the doctrine of equivalents because in-
sufficient evidence supports that it meets any prong of the
function-way-result test. See Appellant Br. 31–41. We
agree with Qiagen that there was insufficient evidence
from which a reasonable jury could have concluded that Qi-
agen’s accused products infringe the ’810 patent. We dis-
cuss each argument in turn.
A
First, Qiagen argues that the district court erred in
denying JMOL of non-infringement by allowing the jury to
conclude that “identical” could mean “identical to a por-
tion.” Appellant Br. 28–29. As noted above, the “second
target-specific primer” requires “a 5′ portion comprising a
nucleic acid sequence that is identical to a second sequenc-
ing primer.” See ’810 Patent Claim Construction Order, at
*1 (emphasis added). But here, it is undisputed that the
accused “second target-specific primer”—Qiagen’s SIP—
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contains 19 nucleotides, while the accused “sequencing pri-
mer” called Read2 contains 34 nucleotides. Despite that
difference in sequence length, Appellees accused the SIP of
satisfying the “second target-specific primer” limitation of
claim 16 because the sequence of the SIP is identical to a
portion of the sequence of Read2 and because identical to a
portion can include identical to the whole. The district
court agreed. Just before trial, it determined that “identi-
cal is an issue of fact for the jury.” J.A. 400. On that basis,
the district court in its JMOL decision concluded that alt-
hough Appellees had to show that the accused SIP con-
tained a sequence identical to Read2, “[t]he jury was not
precluded from finding that ‘identical’ may include identi-
cal to a portion,” and thus the jury’s infringement finding
was supported. Decision, at *6. We disagree.
It was error for the district court to turn a matter of
claim construction over to the jury to decide as a factual
dispute. See O2 Micro Int’l Ltd. v. Beyond Innovation Tech.
Co., 521 F.3d 1351, 1360 (Fed. Cir. 2008) (“When the par-
ties raise an actual dispute regarding the proper scope of
these claims, the court, not the jury, must resolve that dis-
pute.”). As a matter of claim construction, “identical” can-
not mean “identical to a portion” because “identical” means
the same. See, e.g., identical, Webster’s New World College
Dictionary (4th ed. 2009) (“1 the very same 2 exactly alike
or equal”); identical, Merriam-Webster’s Collegiate Dic-
tionary (11th ed. 2003) (“1 being the same . . . 2 having
such close resemblance as to be essentially the same”).
Furthermore, the specification and claims differentiate
the two terms according to their degree. See Seachange
Int’l, Inc. v. C-COR, Inc., 413 F.3d 1361, 1368 (Fed. Cir.
2005) (“[D]ifferent words or phrases used in separate
claims are presumed to indicate that the claims have dif-
ferent meanings and scope” (internal quotation marks and
citation omitted). In particular, where two claim terms dif-
fer by a matter of degree, perhaps by use of a modifier for
one term and not the other, a proper construction should
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give effect to that difference. See, e.g., Arlington Indus.,
Inc. v. Bridgeport Fittings, Inc., 632 F.3d 1246, 1254–55
(Fed. Cir. 2011) (“Reading a [modified version of the spring
metal adaptor] limitation into the [unmodified version of
the] term ‘spring metal adaptor’ would render these addi-
tional modifiers superfluous, which weighs against doing
so.”).
Here, the “second target-specific primer” must be
“identical to a second sequencing primer.” ’810 Patent
Claim Construction Order, at *1 (emphasis added); id. at
*5 (noting that the parties do not dispute that the ’810 pa-
tent defines “second target-specific primer” as having this
requirement (citing ’810 patent col. 16 ll. 33–39)). In con-
trast, the “adaptor primer” of claim 16 need only be “iden-
tical to a portion of the first sequencing primer,” id.
(emphasis added); ’810 patent col. 78 ll. 6–8, where a “por-
tion” of a DNA molecule is defined as comprising all or a
subset of a sequence, see ’810 patent col. 9 ll. 1–5. As Qi-
agen explains and as the specification makes clear, the dif-
ference in specificity is important—the number of
complementary nucleotides impacts the conditions under
which primers anneal to particular sequences. Appellant
Br. 29 (citing ’810 patent col. 13 ll. 58–61 (“Conditions for
primer-target nucleic acid annealing vary with the length
and sequence of the primer[.]”)). Reading the modifier, “a
portion,” into the unmodified term “identical” would render
the modifier language superfluous. See Arlington Indus.,
632 F.3d at 1254–55. Thus, “identical to a portion” cannot
have the same degree of claim scope as “identical.” The
district court therefore erred in allowing the jury to con-
sider that “identical” can mean “identical to a portion,” and
in further denying JMOL to Qiagen on this issue.
B
Next, Qiagen argues that the district court erred in
denying JMOL of non-infringement because no reasonable
jury could have found that the accused SIP satisfies the
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“second target-specific primer” limitation of claim 16. Spe-
cifically, Qiagen argues that the accused SIP does not in-
fringe under the doctrine of equivalents because it fails all
three prongs of the function-way-result test. Again, we
agree.
“The doctrine of equivalents provides a limited excep-
tion to the principle that claim meaning defines the scope
of the exclusivity right in our patent system.” VLSI Tech.
LLC v. Intel Corp., 87 F.4th 1332, 1341 (Fed. Cir. 2023).
Liability under the doctrine, therefore, “is the exception”
and “not the rule.” Id. at 1342 (cleaned up). “[P]roof of
equivalents must be limitation specific, not focused only on
the claim as a whole.” Id. To determine whether the ac-
cused element is an equivalent to a claim limitation, we ask
“whether a substitute element matches the function, way,
and result of the claimed element.” Id. (quoting Warner-
Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 40
(1997)). “Such matching requires that each of function,
way, and result be substantially the same.” VLSI, 87 F.4th
at 1342 (cleaned up). And the “patentee must provide par-
ticularized testimony and linking argument as to the in-
substantiality of the differences between the claimed
invention and the accused device.” Id. (cleaned up).
For each prong of the function-way-result test, the dis-
trict court recounted the parties’ arguments and expert tes-
timony before summarily concluding that the jury had
heard sufficient evidence that it was entitled to credit. De-
cision, at *6–7 (“In the face of conflicting testimony about
whether Qiagen’s products perform substantially the same
function, in substantially the same way, to achieve sub-
stantially the same result, the jury was entitled to credit
Plaintiffs’ evidence.”). But, as we explain below, the evi-
dence provided by Appellees is not exceptional and does not
rise to the level of “particularized testimony and linking
argument” showing substantial similarity between the ac-
cused products and asserted claims in function, way, or
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result. VLSI, 87 F.4th at 1342 (cleaned up). We discuss
each prong of the function-way-result test in turn.
We begin with the “function” prong. The district court
concluded that substantial evidence supported the jury’s
finding that Qiagen’s SIP performs substantially the same
function as the claimed “second target-specific primer.” See
Decision, at *6. We disagree. As Qiagen explains, “[t]he
function of a target-specific primer in the ’810 patent is to
anneal to the known target nucleic sequence to provide a
second specificity step to achieve the desired specificity.”
Appellant Br. 34. Put simply, its function “is to increase
enrichment for the target sequences over non-target se-
quences,” i.e., achieve specificity. Id. Those assertions are
supported by the specification, which explains that the sec-
ond target specific primer “specifically anneals to a portion
of the known target nucleotide sequence.” ’810 patent
col. 16 ll. 35–37 (emphasis added). The specification fur-
ther explains that “‘specific’ when used in the context of a
primer specific for a target nucleic acid refers to a level of
complementarity between the primer and the target such
that there exists an annealing temperature at which the
primer will anneal to and mediate amplification of the tar-
get nucleic acid and will not anneal to or mediate amplifi-
cation of non-target sequences present in a sample.” ’810
patent col. 8 ll. 49–55. Thus, the claimed “second-target
specific primer” is used to facilitate specificity during the
amplification process.
The accused SIP’s function is different. It does not en-
rich the target sequence or provide specificity. Instead, it
ensures that the DNA fragment is compatible with the se-
quencer so that it may be sequenced. J.A. 587. Appellees’
own expert stated as much, explaining that the SIP binds
to a “common sequence” that the GSP adds on by way of a
tail, see J.A. 581, and thus it does not bind to the native
DNA fragment containing the “target” sequence. For that
reason, Appellees’ expert admitted that there was no literal
infringement. See J.A. 581. Nonetheless, the expert went
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on to testify that there was still infringement under the
doctrine of equivalents because, in his view, the SIP works
together with another Qiagen primer, its UP, to perform
substantially the same function as the “second target-spe-
cific primer.” See J.A. 581. But the Qiagen UP is an adap-
tor primer with its own function. See J.A. 592. And while
the ’810 patent’s specification explains that the second tar-
get-specific primer and second adaptor primer work to-
gether, it also explains that the second target-specific
primer performs its own function of enriching the target
sequence, i.e., creating specificity. ’810 patent col. 16 ll. 46–
50 (disclosing that second target-specific primers “can
serve to suppress primer dimers,” i.e., the unwanted off-
target byproduct in PCR); col. 18 ll. 24–29 (describing tar-
get specificity rates). Based on the evidence, no reasonable
jury could have found substantial similarity between the
function of the claimed “second target-specific primer” and
the accused SIP.
Regarding the “way” prong, the “second target-specific
primer” enriches the DNA sample and provides specificity
by being designed against, annealing to, and amplifying a
known target sequence, while specifically not facilitating
the amplification of non-target sequences. ’810 patent col.
16 ll. 33–39; see also ’810 Patent Claim Construction Order,
at *1. The accused SIP does not act in this way; it binds to
a “common sequence” that the GSP adds on by way of a tail,
and not to any target sequence. See J.A. 581. Thus, no
reasonable jury could have found that the SIP acts in a sub-
stantially similar way as the claimed “second target-spe-
cific primer.”
Regarding the “results” prong, the accused SIP also
does not achieve substantially the same “result” as the
“second target-specific primer.” As Qiagen explains, the
SIP amplifies any DNA with the common sequence from
the first round of PCR, rather than selectively enriching
the target sequence. Appellant Br. 38. For example, if first
target-specific primers (i.e., Qiagen’s GSPs) mis-prime on a
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non-target sequence or otherwise interact to produce pri-
mer dimers, the SIP cannot eliminate those off-target am-
plicons from the final pool. Id.; see also ’810 patent col. 16
l. 65–col l. 5. (explaining that target-specific primers “can
interact with each other in an undesired off-target man-
ner”). We therefore conclude that no reasonable jury could
have found that the accused SIP and claimed “second tar-
get-specific primer” produce substantially similar results
based on the evidence.
Thus, the district court erred in denying Qiagen’s re-
newed motion for JMOL of non-infringement under the
doctrine of equivalents for the ’810 patent. Even when
viewing the evidence in the light most favorable to Appel-
lees, there was insufficient evidence from which a reasona-
ble jury could have found liability.
II
Turning to the ’597 patent, the jury found that Qiagen’s
accused products literally infringe claims 1, 5, and 19. De-
cision, at *3. Qiagen argues on appeal that the district
court erred in denying its renewed motion for JMOL of non-
infringement because no reasonable jury could have found
that the accused kits include the claimed “target-specific
primer.” It raises two arguments on appeal. First, Qiagen
argues that insufficient evidence supports the jury’s find-
ing that the accused FP is a “target-specific primer.” Ap-
pellant Br. 44–48. Second, it argues that insufficient
evidence established that sequences in the claimed DNA
interacted with the accused primers to satisfy steps (a) and
(b) of claim 1. Id. at 49–57. We agree that the district court
erred in not granting the renewed JMOL of non-infringe-
ment of the ’597 patent. Because we conclude so on the
basis of Qiagen’s first argument, we need not address its
second.
The district court relied on two primary pieces of evi-
dence to conclude that there was substantial evidence sup-
porting the jury’s finding that the accused FP satisfied the
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“target-specific primer” limitation. Decision, at *4. First,
it explained that the jury heard expert testimony that “‘the
FP primer in the Qiagen workflow, targets the ligated
adaptor’ and thus satisfies the Court’s construction of ‘tar-
get-specific primer.’” Id. (quoting J.A. 591). Second, it ex-
plained that the jury also heard testimony that “the FP
binds to ‘a very small proportion of the molecules’ in a sam-
ple,” id. (quoting J.A. 620), because it only binds to the
adaptor’s compliment.
Appellees’ theory, which relies on the evidence dis-
cussed above and was adopted by the district court, was
accurately described by Qiagen as being “that because
adaptor sequences are added to the DNA fragment that
contains the target sequence, then the FP primer that an-
neals to those newly-added adaptor sequences is annealing
to the same molecule as the actual target sequence.” Ap-
pellant Br. 46 (emphases added); see Appellee Br. 36–38.
But the evidence underlying that theory, even when viewed
in the light most favorable to Appellees, is not substantial
evidence supporting the jury’s infringement finding. While
we agree with Appellees that a DNA fragment and its li-
gated adaptor may, as a combination, contain target and
common sequences, it is not the case that any primer that
simply anneals to any portion of that combined product au-
tomatically satisfies the “target-specific primer” limitation
as construed in the ’597 patent. We discuss the district
court’s errant reliance on such evidence below.
First, the district court’s reliance on the testimony that
the FP “targets the ligated adaptor” is misplaced. Decision,
at *4. As noted earlier, the district court construed “target-
specific primer” to mean “a primer that has a level of com-
plementarity between the primer and the target such
that . . . the primer will anneal to and mediate amplifica-
tion of the target nucleic acid and will not anneal to or me-
diate amplification of non-target sequences present in a
sample.” ’597 Patent Claim Construction Order, at *1 (em-
phases added). The district court further construed “target
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nucleic acid” as a “a nucleic acid molecule of interest (e.g.,
a nucleic acid to be analyzed).” Id. (emphasis added).
Thus, the ’597 patent differentiates between target and
non-target sequences. The “target” refers to that which is
“analyzed” or studied, e.g., the genetic mutation sequence
area, id., whereas a type of non-target sequence is a “com-
mon sequence,” or sequence that is universally present in
all DNA fragments in the sample, see ’597 patent col. 16 ll.
59–61.
Here, the FP targets and anneals to an adaptor—an ar-
tificial sequence “common” to every DNA fragment in the
sample. See J.A. 611 (“All the molecules in the soup have
the adaptor added to it[.]”). That artificial adaptor se-
quence is never “analyzed” because it is a common, artifi-
cial sequence that does not correspond to the “targeted”
genetic mutation sequence. See, e.g., J.A. 522 (explaining
that, based on an inventor’s knowledge and experience,
adaptor sequence is “never” analyzed); see also J.A. 575 (ex-
plaining that PCR “assist[s] folks like clinicians in . . . look-
ing for the mutations”). In other words, the FP targets the
ligated adaptor, which is not the “nucleic acid to be ana-
lyzed.” ’597 Patent Claim Construction Order, at *1 (em-
phasis added). Rather, it is merely an artificial component
that attaches to the ends of that molecule of interest to sup-
port sequencing operations.
Second, the district court’s reliance on testimony that
the FP binds to “a very small proportion of the molecules”
is also misplaced. See Decision, at *4 (quoting J.A. 620).
The FP can be ligated to adaptor sequence regardless of
whether target or non-target sequences are contained by
the sample. See J.A. 532 (Inventor Long Phi Le was asked
“[i]f you have an adapter primer that binds to the universal
oligonucleotide tail adapter, it binds to that adapter if the
adapter is ligated to off-target sequences; right?,” and he
responded, “Correct.”). That the FP binds to “a very small
proportion of the molecules,” then, does not mean that it
cannot or does not bind to molecules that happen not to
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contain target sequence. Thus, the FP is not a “target-spe-
cific primer” because it fails to “not anneal to or mediate
amplification of non-target sequences present in a sample.”
See ’597 Patent Claim Construction Order, at *1 (emphases
added).
Appellees’ response that the FP works in concert with
the GSP to target and amplify sequences and that nothing
in the court’s construction precludes the target-specific pri-
mer from mediating amplification of the target nucleic acid
in concert with another primer is unpersuasive. See Appel-
lee Br. 37. As discussed, the district court’s construction
requires that the “target-specific primer . . . will anneal to
and mediate amplification of the target nucleic acid and
will not anneal to or mediate amplification of non-target
sequences present in a sample.” See ’597 Patent Claim
Construction Order, at *1. It does not allow or suggest, let
alone require, that the “target-specific primer” work in con-
junction with another primer to perform its required func-
tions. On the contrary, the construction specifically
requires the “target-specific primer” to perform the re-
quired functions. Thus, the GSP cannot assist the accused
FP in fulfilling the function of the “target-specific primer.”
See In re Power Integrations, Inc., 884 F.3d 1370, 1377
(Fed. Cir. 2018) (rejecting an argument that permitted two
circuit elements to work in concert to “cause” an action be-
cause “[a]lthough the [subject] patent does not expressly
exclude” the assistance of the second element, “the plain
claim language . . . specifically requires the counter—not
some other circuit element—to ‘caus[e]’ the converter to ad-
just the control input” (citation omitted)). Appellees’ reli-
ance on Qiagen’s GSP is incorrect because it runs counter
to the requirements of the claimed “target-specific primer.”
The district court therefore erred in denying Qiagen’s
renewed motion for JMOL of non-infringement for the ’597
patent. Even when viewing the evidence in the light most
favorable to Appellees, there was insufficient evidence
from which a reasonable jury could have found liability.
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CONCLUSION
We have considered Appellees’ remaining arguments
and find them unpersuasive. For the foregoing reasons, we
reverse the district court’s denial of JMOL of non-infringe-
ment for both patents at issue. The district court should
therefore on remand grant JMOL of non-infringement on
the ’810 and ’597 patents.
REVERSED
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