Abs Global , Inc. v. INGURAN, LLC, doing business as SEXING TECHNOLOGIES

In the
United States Court of Appeals
For the Seventh Circuit
____________________
No. 17-1873
ABS G LOBAL , INC.,
Plaintiff/Counterclaim Defendant-Appellant,
and
G ENUS PLC,
Counterclaim Defendant-Appellant,
v.
INGURAN, LLC, doing business as SEXING T ECHNOLOGIES ,
Defendant/Counterclaim Plaintiff-Appellee,
and
XY, LLC,
Intervening Defendant/Counterclaim Plaintiff-Appellee.
____________________
Appeal from the United States District Court for the
Western District of Wisconsin.
No. 14-CV-503 — William M. Conley, Judge.
____________________
A RGUED FEBRUARY 20, 2018 — D ECIDED J ANUARY 29, 2019
____________________

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2 No. 17-1873
Before WOOD, Chief Judge, and EASTERBROOK and BARRETT ,
Circuit Judges.
WOOD, Chief Judge. This case is about the birds and the
bees—in particular, about human efforts to control the repro-
ductive outcomes otherwise determined by Mother Nature.
Our specific interest is the cattle industry. People have been
raising cattle since the early Neolithic Age, some 10,000 years
ago, when members of the Bovidae family were first domesti-
cated. See Mario Melletti, Cattle Domestication: from Aurochs to
Cow, C AMBRIDGE U NIVERSITY P RESS : FIFTEENEIGHTYFOUR (Feb.
18, 2018), http://www.cambridgeblog.org/2016/02/cattle-do-
mestication-from-aurochs-to-cow/. Not surprisingly, produc-
tion techniques have evolved over the millennia. The innova-
tion at the heart of the present controversy is the development
of sperm-sorting technology. This process enables cattle
breeders to determine the sex of calves by separating a sample
of bull semen into X-chromosome bearing and Y-chromo-
some bearing sperm cells. The resulting product—“sexed se-
men”—is then used to inseminate cows artificially. With this
technology, dairy farmers can be sure they will breed only
milk-producing cows.
Until recently, Inguran, LLC, which does business as Sex-
ing Technologies (“Sexing Tech”), held a monopoly on the
market for sexed cattle semen in the United States. ABS
Global, Inc., which runs a large bull-stud operation, hoped to
change that. Believing that its efforts had been thwarted in
ways that violated the antitrust laws, ABS sued Sexing Tech
in the Western District of Wisconsin in 2014. It alleged, among
other things, that Sexing Tech had unlawfully monopolized
the domestic sexed-semen market in violation of section 2 of

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No. 17-1873 3
the Sherman Act by using its market power to impose coer-
cive contract terms. ABS sought a declaratory judgment pro-
claiming those contracts invalid, hoping to clear the way for
its own entry into that market. Sexing Tech, along with its sub-
sidiary, XY, LLC, (we use “Sexing Tech” to describe them col-
lectively unless the distinction matters) counterclaimed that
ABS infringed its patents and breached the contract between
them by misappropriating trade secrets in developing ABS’s
competing technology. Both sides also added state-law theo-
ries to the mix.
In the end, only three claims went to trial: ABS’s antitrust
claim and Sexing Tech’s patent infringement and breach of
contract counterclaims. After a nearly two-week trial, the jury
returned a mixed—and somewhat puzzling—verdict, which
the court ratified in post-trial rulings. We conclude, as did the
district court, that ABS violated a confidentiality agreement it
had with Sexing Tech, and that Sexing Tech’s patent was not
invalid on obviousness grounds. The jury’s assessments of
two of the three patent claims still at issue, however, cannot
be reconciled under the rules governing dependent claims
and enablement, and so a new trial is necessary on them.
I. The ‘987 Patent
The basic processes at issue in this case are not hard to de-
scribe. They rely on cell sorters, which are devices that sort
cells to select either for a desired characteristic or to weed out
an undesirable characteristic. These sorters date back to the
mid-1960s, but it was not until the early 1990s that the first
person developed a device designed to sort sperm cells. Law-
rence Johnson, then a scientist with the U.S. Department of
Agriculture, was the inventor. His technique is best explained
with the help of a diagram:

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4 No. 17-1873
This technique is a variation on a standard cell sorting
technique called flow cytometric sorting. Johnson’s process
begins with a sample of stained sperm cells suspended in liq-
uid. The stain allows the sorter to distinguish X-bearing cells
from Y-bearing cells based on differences in their DNA con-
tent. The stained fluid is forced through a stream, spacing out
the cells and orienting them single-file. Next, a laser identifies
each cell as bearing either an X or Y chromosome. By this time,
each sperm cell is contained in an individual droplet, and a
different charge is applied to each droplet depending on
whether it contains an X- or Y-bearing sperm cell. The indi-
vidually charged cells are then passed through charged
plates, which redirect the cells into three batches: X-bearing
cells, Y-bearing cells, and waste. Because the cells are sorted
while they are suspended in individual water droplets, this
device is called a “droplet sorter.” Johnson first patented this

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No. 17-1873 5
technology in 1992 and wrote an article discussing improve-
ments to the technique in 1999.
Sexing Tech holds a patent—U.S. Patent Number 8,206,987
(“the ’987 patent”)—over an alternative technique, developed
by Gary Durack, for sorting sperm cells. The Durack patent
issued in 2012, with an effective filing date relating back to a
provisional application filed on March 28, 2003. Although the
full text of the patent runs nearly 250 pages, the critical part
for our purposes is the final section, where the claims covered
by the patent are set out. Three of those claims are at issue in
this case: Claims 1, 2, and 7. Claim 1 is an independent claim,
meaning (as we explain more fully below) that it stands on its
own, while Claims 2 and 7 are dependent claims. Each of the
dependent claims begins by specifying “a method of sorting
a mixture of stained sperm cells according to claim 1.” Each
dependent claim then goes on to specify a limitation on the
subject matter covered by Claim 1, as required by 35 U.S.C.
§ 112(d). We set forth the full text of the disputed claims in the
Appendix to this opinion.
The invention described in Claim 1 follows the same basic
structure as the Johnson invention, but it substitutes a
different method for sorting the cells at the final step. The
Johnson method uses magnets to redirect droplets depending
on the cell they contain, while the ’987 patent describes a
photo-damage sorting method. Photo-damage sorting is
straightforward: a “kill laser” destroys undesired cells
identified by the detection laser, leaving only the desired cells
alive. The end product of the two methods is thus different:
the Johnson patent yields three separate outputs
(characteristic A, characteristic B, and waste); the Durak
patent (illustrated below) produces only one output, which is

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6 No. 17-1873
composed of living cells with the desired characteristic (A or
B) and dead waste cells. Under ideal conditions, photo-
damage sorters work faster than droplet sorters because their
speed is not limited by the size of droplets.
Dependent Claims 2 and 7 impose additional limitations
on Claim 1 of the ’987 patent. Claim 7 specifies that in the final
step of Claim 1, “Characteristic A” must be “a live X-
chromosome bearing sperm cell” and “Characteristic B” must
be “something other than a live X-chromosome bearing sperm
cell.” This means that a photo-damage sorter that sorts sperm
cells for a characteristic other than sex (perhaps a set of genes
on a different chromosome) would infringe Claim 1 of the
patent, but not Claim 7. It also means that every violation of
Claim 7 would necessarily violate the broader Claim 1.
Claim 2 restricts Claim 1 in a different way. Claim 2 covers
a process “wherein the step of selecting stained sperm cells in
the flow path to photo-damage further comprises the step of
photo-damaging sperm cells based upon a sort strategy.”
Thus, the only difference between Claim 1 and Claim 2 is
whether the “selection” of stained sperm cells that occurs at
the selection point (step (e) of Claim 1), is based solely on their
classification as having characteristic A or B (Claim 1) or
based both on their classification as A or B and a sort strategy
(Claim 2) that would further narrow the results obtained. A
photo-damage sorter that sorts sperm without an additional
sort strategy would infringe Claim 1 of the patent, but not
Claim 2, while all sorters that followed all of the Claim 1 steps
and then implemented a sort strategy would violate both
Claim 2 and Claim 1.

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No. 17-1873 7
Although Sexing Tech holds a patent for photo-damage
sorting of sperm cells, it had not commercialized the technol-
ogy before this suit began—its commercial sorters all used the
droplet sorting technique pioneered by Johnson. ABS says
that it created its own commercially usable photo-damage
sorter but found itself blocked by Sexing Tech’s patents,
bringing us to the present litigation.
II. The Issues on Appeal
As we noted earlier, the jury reached a mixed verdict. It
found that Sexing Tech had violated section 2 of the Sherman
Act, but that ABS suffered no antitrust injury from that viola-
tion and thus was entitled only to injunctive relief. On the
other hand, the jury found ABS liable for infringing the ‘987
patent and a second patent held by Sexing Tech,1 and it con-
cluded that ABS had breached its confidentiality contract with
Sexing Tech. It accordingly awarded damages to Sexing Tech
on those claims. With respect to the ’987 patent, ABS argued
only invalidity; it did not contest infringement. The jury
found that independent Claim 1 and dependent Claim 7 of
the ‘987 patent were valid, but that dependent Claim 2 was
invalid. After trial, both parties moved for judgment as a mat-
ter of law, and ABS also moved for a new trial and for a per-
manent injunction. The district court granted those motions
in part and denied them in part, and it entered a permanent
injunction barring Sexing Tech from enforcing certain con-
tractual provisions as a remedy for its antitrust violation. ABS
appealed. (Sexing Tech initially filed a cross-appeal, which it
later voluntarily dismissed.)
1 The other patent at issue in the district court, U.S. Patent No.
8,198,092, plays no part in this appeal, and so we disregard it.

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8 No. 17-1873
Three issues are now before us: two relate to patent law
and one to contract interpretation. First, ABS argues that all
three claims in the ‘987 patent are invalid on the ground of
obviousness. See 35 U.S.C. § 103. Second, ABS contends that
the jury’s decisions to uphold independent Claim 1 and de-
pendent Claim 7, but to find dependent Claim 2 invalid, are
irreconcilably inconsistent under the rules for enablement
and thus a new trial is necessary. Finally, ABS asserts that the
district court erred by finding a breach of the confidentiality
agreement. It admits that it hired a former employee of Sexing
Tech’s subsidiary XY, and that this employee brought pur-
loined trade secrets with her to ABS. Indeed, ABS stipulated
to trade-secret liability for this wrongdoing, but Sexing Tech
wanted and got more: the court held that ABS was separately
liable for breach of a confidentiality agreement between the
companies. ABS contends that information passed along by a
disloyal former employee was not covered by the agreement
and thus that it was entitled to judgment on this point.
III. Appellate Jurisdiction
Because it is rare for our court to see a patent case, we take
a moment to examine our appellate jurisdiction. The Federal
Circuit has exclusive jurisdiction over any “appeal from a fi-
nal decision of a district court of the United States … [1] in
any civil action arising under, or [2] in any civil action in
which a party has asserted a compulsory counterclaim arising
under” the Patent Act (“the Act”). 28 U.S.C. § 1295(a)(1); FED.
R. C IV. P. 13(a). We lack appellate jurisdiction if either basis
for the Federal Circuit’s exclusive jurisdiction was present in
the district court, regardless of the claims brought on appeal.
See Kennedy v. Wright, 851 F.2d 963, 965 (7th Cir. 1988).

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No. 17-1873 9
Our first inquiry is whether, applying the well-pleaded
complaint rule, this case arose under the patent laws. Chris-
tianson v. Colt Indus. Operating Corp., 486 U.S. 800, 809 (1988).
Following long-established law, the Supreme Court held in
Christianson that the complaint had to establish “either that
federal law creates the cause of action or that the plaintiff’s
right to relief necessarily depends on resolution of a substan-
tial question of federal law.” Id. at 808 (quoting Franchise Tax
Bd. v. Constr. Laborers Vacation Trust, 463 U.S. 1, 27–28 (1983)).
For patent cases, the well-pleaded complaint must “estab-
lish[] either that federal patent law creates the cause of action
or that the plaintiff’s right to relief necessarily depends on res-
olution of a substantial question of federal patent law, in that
patent law is a necessary element of one of the well-pleaded
claims.” Id. at 809. In our case, ABS’s complaint had nothing
to do with patent law: it invoked only federal antitrust law
and state law. Thus, under Christianson this is not a case that
arises under the patent laws, and the first potential source of
the Federal Circuit’s jurisdiction does not apply.
The second possibility—jurisdiction through a compul-
sory counterclaim—requires more attention. Patent issues en-
tered this case when Sexing Tech filed a counterclaim assert-
ing patent infringement. If that counterclaim was compul-
sory, this appeal belongs in the Federal Circuit; if it was per-
missive, it is properly in this court. Section 1295(a) incorpo-
rates the standard of Federal Rule of Civil Procedure 13(a) for
determining whether a counterclaim is compulsory. In re
Rearden LLC, 841 F.3d 1327, 1332 (Fed. Cir. 2016). In applying
Rule 13(a), the Federal Circuit examines “(1) whether the legal
and factual issues raised by the claim and counterclaim are
largely the same; (2) whether substantially the same evidence
supports or refutes both the claim and the counterclaim; and

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10 No. 17-1873
(3) whether there is a logical relationship between the claim
and the counterclaim.” Id. Our test adds a few additional
points: we require that the claim (1) exist at the time of plead-
ing, (2) arise out of the same transaction or occurrence as the
opposing party’s claim, and (3) not require for adjudication
parties over whom the court may not acquire jurisdiction.”
Burlington N. Ry. Co. v. Strong, 907 F.2d 707, 710–11 (7th Cir.
1990).
The difference between these standards is immaterial for
this case. Sexing Tech’s claim existed at the time of pleading,
and it does not require any additional parties, and so we need
to assess only the “transaction or occurrence” requirement. To
determine whether a claim arises from “the same transaction
or occurrence,” this circuit uses the “logical relationship” test,
which requires us to examine the factual allegations underly-
ing each claim. Id. at 711. The patent and antitrust claims in
this case are quite different. ABS’s antitrust claims hinge on
Sexing Tech’s competitive practices, such as the use of ever-
green clauses in its contracts and other allegedly coercive ap-
plications of market power. ABS did contend that Sexing Tech
pooled patents for anticompetitive reasons, but the pooling of
patents is distinct from questions of infringement and valid-
ity. Any relation between the patent and antitrust claims is
minor. In fact, patent counterclaims are frequently permissive
in antitrust cases. To hold otherwise “would be to hold that
the holder of a patent, which is presumptively and facially
valid … must immediately counterclaim with any and every
and even, perhaps, every potential claim of infringement
against that plaintiff or else lose such claims forever.” Xerox
Corp. v. SCM Corp., 576 F.2d 1057, 1061 (3d Cir. 1978) (citation

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No. 17-1873 11
omitted). The patent counterclaims in this case were permis-
sive, and thus the appeal falls outside of the Federal Circuit’s
exclusive jurisdiction and is properly in this court.
IV. Obviousness
The patent system is built on a trade-off. On one side of
the ledger, the prospect of exclusivity gives inventors an in-
centive both to innovate and to disclose their inventions, to
the benefit of society as a whole. Without the prospect of a
patent, inventors may choose other pursuits or hide their in-
novations from the public. See Kewanee Oil Co. v. Bicron Corp.,
416 U.S. 470, 480–82 (1974) (noting the tradeoff between pa-
tent protection and trade-secret protection). On the other
hand, a patent comes at a social cost: the exclusivity given to
the inventor prevents competition with respect to the subject
matter of the patent for 20 years, see 35 U.S.C. § 154(a)(2), in-
creasing prices for users and preventing future innovators
from building on or improving the invention without a li-
cense. The patent system may not calibrate those opposing in-
centives perfectly, see generally Stephen Yelderman, The Value
of Accuracy in the Patent System, 84 U. C HI. L. R EV. 1217 (2017),
but we are not in the habit of demanding perfection from leg-
islation.
Nonetheless, the Patent Act includes a number of doc-
trines that are designed in the aggregate to come as close as
possible to the socially optimal balance. Prime among them is
the bar against the patentability of obvious inventions, which
the Supreme Court recognized as a constitutional “absolute
prerequisite to patentability” even before Congress codified
the requirement in 1952. Dann v. Johnston, 425 U.S. 219, 225–
26 (1976); see also Great Atl. & Pac. Tea Co. v. Supermarket Equip.
Corp., 340 U.S. 147, 155 (1950) (Douglas, J., concurring) (“The

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12 No. 17-1873
standard of patentability is a constitutional standard … .”).
Extending patent protection to obvious inventions would
“withdraw[] what already is known into the field of its mo-
nopoly and diminish[] the resources available to skillful
men.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007)
(quoting Great Atl. & Pac. Tea Co., 340 U.S. at 152–53). As the
Act now provides, an invention cannot be patented if it
“would have been obvious … to a person having ordinary
skill in the art to which the claimed invention pertains.” 35
U.S.C. § 103.
The Supreme Court has held that “[t]he ultimate judgment
of obviousness is a legal determination.” KSR, 550 U.S. at 427.
In making that determination, courts should adopt the per-
spective of a skilled artisan not only of “ordinary skill” but
also of “ordinary creativity,” who would follow “known op-
tions within his or her technical grasp” to solve known prob-
lems. Id. at 421. ABS says that the ’987 patent would have been
obvious at the time of its invention to a skilled artisan because
it merely replaced the traditional droplet method for sorting
sperm cells with the photo-damage method, which had been
successfully used to sort other types of cells. Sexing Tech re-
sponds that there were many factors that would have made
photo-damage sorting unlikely to work with sperm cells and
thus experimenters would have been discouraged from trying
to combine the methods. The jury in the present case found
that ABS had infringed Sexing Tech’s ‘987 patent; it thus had
to have found that the innovation was not obvious. ABS con-
tends that this was error and that all three of the claims at is-
sue are invalid for obviousness. Before resolving this dispute,
we say a word about the applicable standard of review.

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No. 17-1873 13
A. Standard of Review
In Graham v. John Deere Co. of Kansas City, 383 U.S. 1, 17
(1966), the Supreme Court held that obviousness is a question
of law. See also KSR, 550 U.S. at 427. This flows from the
Court’s acknowledgement that the standard for patentability
is “basically constitutional.” Anderson’s-Black Rock, Inc. v.
Pavement Salvage Co., 396 U.S. 57, 62–63 (1969). It also reflects
the Court’s judgment that the question whether an invention
meets the criteria of Article I, section 8, clause 8 of the Consti-
tution requires the application of one of those broad legal
standards that calls for de novo review by appellate courts. See
U.S. Bank Nat’l Assn. v. Village at Lakeridge, LLC, 138 S. Ct. 960,
966–67 (2018); Ornelas v. United States, 517 U.S. 690, 697–98
(1996). Nevertheless, like many legal questions, the obvious-
ness question “lends itself to several basic factual inquiries.”
Graham, 383 U.S. at 17. We review those basic or historical
facts only for clear error. U.S. Bank, 138 S. Ct. at 966.
As with any appeal from a motion for judgment as a mat-
ter of law, we must review all of the evidence in the record in
the light most favorable to the nonmoving party, drawing all
reasonable inferences in that party’s favor. Reeves v. Sanderson
Plumbing Prods., Inc., 530 U.S. 133, 150–51 (2000). As applied
here, this means that we must assume that the jury settled the
underlying facts relevant to obviousness in Sexing Tech’s fa-
vor. And we note that Sexing Tech has already prevailed on
this issue in a different context: after the U.S. Patent and
Trademark Office granted the ‘987 patent, ABS unsuccessfully
challenged it in an inter partes review proceeding, under
which ABS had only the burden of showing a reasonable like-
lihood of prevailing. See 35 U.S.C. §§ 311, 314(a).

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14 No. 17-1873
In Graham, the Supreme Court highlighted three core fea-
tures that are pertinent to obviousness: (1) “the scope and con-
tent of the prior art,” (2) “differences between the prior art and
the claims at issue,” and (3) “the level of ordinary skill in the
pertinent art.” 383 U.S. at 17. “Secondary considerations”
such as “commercial success, long felt but unsolved needs,
[and] failure of others,” are also potentially relevant. Id. at 17–
18. These are all underlying facts—a point that becomes clear
when we recall that in a bench trial on obviousness, “‘subsid-
iary determinations of the District Court’ [are] subject to Rule
52(a)’s clear error standard.” Teva Pharm. USA, Inc. v. Sandoz,
Inc., 135 S. Ct. 831, 838–39 (2015) (quoting Dennison Mfg. Co. v.
Panduit Corp., 475 U.S. 809, 811 (1986) (per curiam)).
B. The Jury’s Verdict
ABS argues that “for the most part the relevant facts were
not disputed.” Sexing Tech takes the opposite position, con-
tending that factual disputes abounded. It asserts that
whether an artisan would have been “motivated to combine”
the prior art is itself a factual question. Sexing Tech asserts
that the jury implicitly concluded that the prior art “teaches
away” from the ’987 patent’s use of a photo-damage method.
But that is hard to say, especially in a case such as this one,
where the jury rendered only a general verdict. Special ver-
dicts are the only reliable way to nail down such findings. See
FED. R. C IV. P. 49(a); Roberts v. Sears, Roebuck & Co., 723 F.2d
1324, 1341–42 (7th Cir. 1983) (en banc).
The mystery question concerns what the jury might have
thought about the motivation to combine Johnson’s droplet
sorter with a photo-damage method. In the Federal Circuit,
motivation to combine is always a factual question that is
“[s]ubsumed within the Graham factors.” Pfizer, Inc. v. Apotex,

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No. 17-1873 15
Inc., 480 F.3d 1348, 1361 (Fed. Cir. 2007); see also Wyers v. Mas-
ter Lock Co., 616 F.3d 1231, 1238–39 (Fed. Cir. 2010). That court
asks “whether there is a known reason a skilled artisan would
have been motivated to combine elements to arrive at a
claimed combination.” Arctic Cat Inc. v. Bombardier Recrea-
tional Prods. Inc., 876 F.3d 1350, 1359 (Fed. Cir. 2017). Here, to
the extent that there are disputes about the existence of some-
thing that would give an artisan a “known reason” to combine
prior art elements, the jury’s verdict indicates that it resolved
those factual questions in favor of Sexing Tech.
Nevertheless, it does not follow, as Sexing Tech contends,
that the existence of factual disputes by itself makes judgment
as a matter of law inappropriate. Sexing Tech’s position over-
states the importance of a motivation to combine or “teaching
away” after KSR. KSR recognizes that “expert testimony …
may resolve or keep open certain questions of fact,” but
“[t]hat is not the end of the issue.” 550 U.S. at 427. Some fac-
tors might point away from obviousness and other factors
might point toward it, yet judgment as a matter of law might
be appropriate. That is because the jury does not have the last
word on obviousness; as we noted earlier, it is the court that
must resolve the ultimate legal issue.
C. Nonobviousness of ‘987 Patent
Out of all the evidence that was presented, only a small
portion bears on the question whether the ’987 patent was in-
valid for obviousness. See 35 U.S.C. § 103. There were three
pieces of documentary evidence: (1) Johnson’s 1999 article de-
scribing his droplet method of sperm sorting; (2) a book chap-
ter written by Jan Keij describing other applications of photo-
damage sorting; and (3) the ’987 patent itself. In addition,

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16 No. 17-1873
three witnesses opined on the relation among the three de-
vices: Durack, the inventor of the ’987 patent; J. Paul Robin-
son, ABS’s expert; and John Nolan, Sexing Tech’s expert.
We already have discussed the ’987 patent and Johnson’s
basic method: the former uses a kill laser to sort sperm cells,
while the latter uses droplet sorting. ABS contends that the
book chapter written by Keij, titled “High-Speed Photo-
damage Cell Sorting: An Evaluation of the ZAPPER Proto-
type,” provides a bridge from Johnson’s work to the ’987 pa-
tent. In the book, which was released in 1994, Keij describes
the potential applications for a prototype photo-damage
sorter he had created. The main benefit of his technique was
speed: whereas a droplet sorter topped out at 40,000 sorts per
second, a photo-damage sorter could reach 5,000,000 sorts per
second. Keij opines that “[s]orting of X or Y chromosome
bearing sperm cells for insemination (Johnson et al., 1989) is
an interesting possibility.” But he also mentions some draw-
backs of the technique. The forces involved could kill cells at
higher speeds, and tradeoffs would need to be made between
yield and purity given imperfections in the kill-laser system.
A good portion of the trial testimony was spent teasing out
the implications of Keij’s work for sperm sorting. While ABS
and Sexing Tech hotly contested those facts, they agreed on
many others. There is no real dispute over what counts as
prior art, the level of skill for someone having ordinary skill
in the art, or over many secondary factors. Yet there were
some clashes, including over the question whether it would
have been obvious to a skilled artisan to use Keij’s photo-
damage method in a sperm cell sorter. Three disputes con-
cerning Keij’s work were particularly important.

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No. 17-1873 17
First, two of the witnesses questioned whether Keij actu-
ally had rendered the techniques discussed in his article prac-
ticable at the time the article was written. Keij’s book chapter
gives the impression that he had done so, but that was not
clear. On cross, ABS’s expert Robinson admitted that he pre-
viously told the Patent Office that “the methods discussed in
Keij were not at the time of publication operable even on the
cells discussed therein.” Durack characterized Keij’s assess-
ments as “optimistic.”
Second, the parties disputed how the physical properties
of sperm cells would stand up against Keij’s photo-damage
technique. Nolan testified that sperm cells are “large cells”
with “fragile aspects,” because sperm cells lack the DNA re-
pair mechanisms that are present in other types of cells. Be-
cause Keij’s kill laser was “leaky”—meaning it could not pre-
cisely and fully be turned off—these fragilities were worri-
some. Yet other testimony suggested that these characteristics
might not matter: Durack testified that the things that Keij
thought might damage cells—sheer forces from the increased
speeds of a photo-damage sorter—were not a problem for
sperm cells. Durack identified the real weakness deterring the
adoption of photo-damaging sperm as the lack of a proper
digital signal processer, which would allow the laser to sort
more effectively.
Third, the parties disputed whether a skilled artisan
would have had reason to think that photo-damage sorting
could really work faster than droplet sorting when applied to
sperm cells. Lawrence’s 1999 article outlining the state of the
art in droplet sorting of sperm cells was written after the Keij
book chapter. By that time Lawrence had improved the speed
of droplet sorters. Characteristics specific to sperm cells are

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18 No. 17-1873
likely to lower the top speeds otherwise possible through
photo-damage techniques. This was enough to create a factual
dispute over how much speed a reasonable artisan at the time
could have expected to gain by switching to photo-damage
sorting.
That brings us to the ultimate question: obviousness. Pa-
tents are presumed to be valid under 35 U.S.C. § 282(a). In-
deed, the Supreme Court held in Microsoft Corp. v. i4i Limited
Partnership that invalidity must be proved by clear and con-
vincing evidence. 564 U.S. 91, 95 (2011). With that in mind, we
turn to the Supreme Court’s decision in KSR, which is its most
recent pronouncement on obviousness. There, the patent was
an adjustable pedal with a fixed pivot point and an electronic
sensor attached to the fixed point. KSR, 550 U.S. at 411–12. The
prior art also included an adjustable mechanical pedal with a
fixed pivot point and other adjustable pedals with electronic
sensors. Id. at 408–09. The Federal Circuit found the innova-
tion nonobvious (and thus patentable) because, while it may
have been obvious to try combining the existing pedals, that
was not enough to render the invention obvious for patent
purposes. Id. at 414. The Supreme Court reversed, holding
that when “there are a finite number of identified, predictable
solutions” that “lead[] to the anticipated success, … the fact
that a combination was obvious to try might show that it was
obvious under § 103.” Id. at 421.
This case is similar to KSR. The ’987 patent discloses three
methods known in the art for sorting cells: droplet sorting,
photo-damage sorting, and fluid switching (a third method
for sorting cells not otherwise at issue). Until that patent is-
sued, sperm cells had been sorted only through droplet sort-

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No. 17-1873 19
ing. Thus, as in KSR, the ’987 patent substituted an “identi-
fied, predictable solution[]”—photo-damage sorting—into an
existing sperm-sorting apparatus. Id. If that were all we had,
we might be inclined to find that the ‘987 patent failed for ob-
viousness. But the record paints a more complex picture. Tak-
ing the facts in the light most favorable to Sexing Tech, we see
significant support for nonobviousness and thus patentabil-
ity: existing photo-damage sorters were more flawed than
Keij implied; droplet sorters’ speed had improved, narrowing
the speed gap; and sperm cells differ in important ways from
other commonly sorted cells.
KSR emphasizes that an invention may be obvious as a
matter of law if it employs a “predictable solution” to a
known problem. Id. The known problem identified by ABS is
the need to increase sort speed. Many of the disputed facts
suggest that photo-damage sorting would not have been ob-
vious even to try to fix this problem. For the final product—
sexed semen—to be commercially usable, a sorter must
achieve a high degree of purity. Witnesses testified that Keij’s
photo-damage method would result in potentially large
trade-offs in purity and viability, with limited gains in speed.
Viewed in this light, Durack did more than would be obvious
to a reasonable artisan—even a creative one—by conceiving
of a photo-damage sorter that could overcome these road-
blocks. (ABS separately argues that Durack did not succeed in
that endeavor—meaning that his invention did not suffi-
ciently enable his device—but enablement is different from
obviousness. We address enablement below.) An inventor
who finds a way to make workable an alternative that had
been rejected as impracticable has done more than implement
an obvious combination. We conclude that the ‘987 patent was

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20 No. 17-1873
nonobvious, and thus that the district court was correct to
deny ABS’s motion to invalidate it on that ground.
V. Enablement of Dependent Claim 2
Even though the ‘987 patent does not fail for obviousness,
another problem looms: the question whether the jury was
fatally inconsistent in its findings that independent Claim 1 of
the patent was valid, but that Claim 2, a dependent claim
derivative of Claim 1, was not. ABS argues that this
discrepancy sinks the verdict for Sexing Tech. Since we have
ruled out obviousness as a ground for striking down the
entire patent, that leaves only enablement as a possible
problem on this record. According to Sexing Tech, the jury
could validly have found that the dependent claim was not
enabled (and thus was invalid), while finding at the same time
that the independent claim was enabled (and thus valid). ABS
argues to the contrary that this is logically impossible: an
independent claim must encompass all features of the
dependent claim, and thus one cannot have an enabled
independent claim with a non-enabled dependent claim.2 If the
verdicts are indeed irreconcilable, then ABS is entitled to a
new trial. ABM Marking, Inc. v. Zanasi Fratelli, S.R.L., 353 F.3d
541, 543 (7th Cir. 2003).
This issue requires us to examine two more doctrines of
patent law: the distinction between independent and depend-
ent claims, and the enablement requirement. The Patent Act
speaks to both of these.
2 The converse is possible: a dependent claim might be enabled even
if the independent claim is not, if the independent claim overreached or
was otherwise too broad.

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No. 17-1873 21
A. Independent versus Dependent Claims
Section 112 of the Act addresses independence and de-
pendence:
(c) Form.—A claim may be written in independent
or, if the nature of the case admits, in dependent or
multiple dependent form.
(d) Reference in Dependent Forms.—Subject to
subsection (e), a claim in dependent form shall contain
a reference to a claim previously set forth and then
specify a further limitation of the subject matter
claimed. A claim in dependent form shall be construed
to incorporate by reference all the limitations of the
claim to which it refers.
35 U.S.C. § 112(c), (d). The difference between the two types
of claims is critical to the question before us. As one treatise
puts it:
… [I]ndependent claims are free-standing. The scope
of an independent claim can therefore be determined,
at least in theory, by referring to that claim only and
not to any other claims in the patent. Dependent
claims, in contrast, incorporate the contents of a pre-
ceding claim by reference. The scope of a dependent
claim cannot be ascertained without referring to the
claim from which it depends.
1 MOY’ S WALKER ON P ATENTS § 4:102 (4th ed.). With this in
mind, we can see that Claims 2 and 7—both of which specify
a method “according to Claim 1”—can only be dependent
claims. The finding of an inconsistency between Claim 1 and

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22 No. 17-1873
Claim 2 cannot, therefore, be salvaged by considering them to
be two entirely different patents, nor did either party ever
press such an argument. Indeed, the parties accepted the
claims construction provided by the district court. Any com-
plaint about the court’s conclusion that would amount to as-
serting a new claim construction for Claim 2 (e.g., an assertion
that it is an independent rather than a dependent one) is thus
waived. See Interactive Gift Express, Inc. v. Compuserve Inc., 256
F.3d 1323, 1346–47 (Fed. Cir. 2001).
As we have stressed, a dependent claim “must be nar-
rower than the claim upon which it depends and must not be
broader in any respect.” 3 D ONALD S. C HISUM, C HISUM ON
P ATENTS § 8.06[5] (2018) (cited as CHISUM); AK Steel, 344 F.3d
at 1242. When faced with incompatibilities in dependent and
independent claims, the rules of claim construction oblige
courts to reconcile them. “Dependent claims often play an im-
portant role in determining the scope of the claims upon
which they depend.” 3 CHISUM, § 8.06[5]. “Under the doctrine
of claim differentiation, each claim in a patent is presump-
tively different in scope.” Wenger Mfg., Inc. v. Coating Mach.
Sys., Inc., 239 F.3d 1225, 1233 (Fed. Cir. 2001).
The idea of claim differentiation, while unique to patent
law, is closely related to rules of contract or statutory inter-
pretation designed to give meaning to each provision of a con-
tract or statute. It instructs that “dependent claims are pre-
sumed to be of narrower scope than the independent claims
from which they depend.” AK Steel Corp., 344 F.3d at 1242; see
Wenger Mfg., 239 F.3d at 1234 (finding that because dependent
claim is limited to “recirculation” of air, independent claim
included device that either circulated or recirculated air). One
consequence of the “document-as-a-whole” perspective is

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No. 17-1873 23
that for purposes of claim construction, courts may look to
dependent claims to ascertain the full scope of independent
claims. Alcon Research, Ltd. v. Apotex Inc., 687 F.3d 1362, 1367
(Fed. Cir. 2012). Dependent claims may broaden the court’s
interpretation of the scope of an independent claim to ensure
that the dependent claims fit within its scope. Id. at 1367–68.
On the other hand, a dependent claim may sink an independ-
ent claim by revealing that the full scope of the independent
claim is unpatentable. Id.
B. Enablement in General
Enablement is defined by the Patent Act, which requires
that the specification of a patent “contain a written description
of the invention” in “such full, clear, concise, and exact terms
as to enable any person skilled in the art … to make and use
the same … .” 35 U.S.C. § 112(a). Enablement is, at its heart,
the requirement that the inventor reveal how the invention
works. (The separate written-description requirement ad-
dresses what the invention is.) A crucial part of the inventor’s
end of the grand patent bargain is the inventor’s full disclo-
sure of the invention. “The scope of the claims must be less
than or equal to the scope of the enablement to ensure that the
public knowledge is enriched by the patent specification to a
degree at least commensurate with the scope of the claims.”
AK Steel Corp. v. Sollac & Ugine, 344 F.3d 1234, 1244 (Fed. Cir.
2003) (quoting Nat’l Recovery Techs. v. Magnetic Separation Sys.,
Inc., 166 F.3d 1190, 1195–96 (Fed. Cir. 1999)) (internal quota-
tion marks and alterations omitted). Dependent claims are
subsets of an independent claim.
Sexing Tech recognizes that broad point, but it suggests
that the jury’s verdicts here are reconcilable because the “fur-
ther limitation” specified in dependent Claim 2—the use of a

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24 No. 17-1873
sort strategy—may have required it to provide additional in-
structions beyond what it supplied to support Claim 1. In
other words, Sexing Tech argues that aspects of Claim 2 are
broader than Claim 1. It concludes that the absence of addi-
tional information required to enable the broader parts of
Claim 2 explains the jury’s verdict. In our view, however, this
fundamentally misunderstands the nature of a dependent
claim.
Three examples illustrate the difference between the par-
ties’ positions:
Example 1: The independent claim has three elements,
ABC. A dependent claim could be limited to fewer ele-
ments and thus describe a narrower piece of the inven-
tion, AB or BC.
Ex. 1
Example 2: The independent claim has three elements,
ABC, but element C can be accomplished in two differ-
ent ways or has independently valuable variants, C 1
and C 2 . A dependent claim would then limit the origi-
nal claim by specifying the particular variant of C, and
describe an invention with elements ABC1 (dependent
claim #1), or ABC 2 (dependent claim #2).
ABC
AB BC

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No. 17-1873 25
Ex. 2
Example 3: The independent claim has three elements,
ABC. The inventor then wants to patent an invention
whose limitation requires an additional process, ele-
ment D. The inventor asserts that claim ABCD is de-
pendent on claim ABC. D, however, is not contained
within the scope of the independent claim.
Ex. 3
Sexing Tech contends that what we have before us is an
instance of Example 3. The failure adequately to describe ele-
ment D, in this case the “sort strategy,” it says, might be the
source of the lack of enablement for the dependent claim. It
believes that the jury’s problem with Claim 2 was that it de-
scribes a non-enabled superset of Claim 1 rather than a nar-
rower subset of that claim.
The problem with Sexing Tech’s logic, as we already have
shown, is that a dependent claim cannot include elements that
ABC
ABC1 ABC2
ABC
ABCD

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26 No. 17-1873
are not found within the independent claim. What Sexing
Tech is necessarily arguing, therefore, is that Claim 2 is not in
fact a dependent claim reliant on—and importantly, narrower
than—Claim 1. While “[t]he interpretation of a patent claim is
exclusively a matter of law for the court.” ABS Glob., Inc. v.
Inguran, LLC, No. 14-CV-503-WMC, 2016 WL 3963246, at *21
(W.D. Wis. July 21, 2016) (citing Markman v. Westview Instru-
ments, Inc., 517 U.S. 370, 372 (1996)), that does not mean that a
party can save such an argument for appeal. At summary
judgment, the district court interpreted Claims 1 and 2, and
not only upheld Claim 2’s status as a dependent claim but re-
lied on Claim 2’s identity as a narrower subset of Claim 2 to
interpret Claim 1. That much was established when the jury
received the case, and it had no power to revisit that interpre-
tation of the two claims. In other words, the district court con-
cluded before trial that Claims 1 and 2 are represented by Ex-
ample 2, not Example 3.
It is possible for an inventor to add to an existing patent in
the manner illustrated by Example 3, but that is done with an
improvement patent, which adds an additional element not
within the scope of original patent. That theory is not availa-
ble, however, at this stage of the present case. No one ever
argued that Claim 2 is an improvement patent that can stand
on its own. Moreover, nothing in the jury’s verdict requires us
to upset the court’s construction of the claims and to adopt an
entirely new theory. As we now explain in greater detail, the
nature of dependent claims and the requirements for enable-
ment defeat Sexing Tech’s efforts to reconcile the verdicts on
Claim 1 and Claim 2.
Enablement is a practical doctrine that allows for breadth
without the need for undue specificity. It is well established

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No. 17-1873 27
that “[t]he full scope of the claimed invention must be ena-
bled.” Sitrick v. Dreamworks, LLC, 516 F.3d 993, 999 (Fed. Cir.
2008); see also Christianson v. Colt Indus. Operating Corp., 870
F.2d 1292, 1299 (7th Cir. 1989) (“If the invention can be repro-
duced in its entire scope, then the patent specifications are en-
abling.”).
The enablement requirement is satisfied when “one
skilled in the art, after reading the specification, could practice
the claimed invention without undue experimentation.” AK
Steel Corp., 344 F.3d at 1244 (emphasis added). Enablement
does not require perfectly precise and complete instructions;
it demands only that skilled persons will be able to practice
the invention after “reasonable” experimentation. ALZA Corp.
v. Andrx Pharmaceuticals, LLC, 603 F.3d 935, 940 (Fed. Cir.
2010). For a broad claim to be sufficiently enabled, the speci-
fication need not “describe how to make and use every possi-
ble variant of the claimed invention … [since] knowledge of
the prior art and routine experimentation can often fill gaps,
interpolate between embodiments, and perhaps even extrap-
olate beyond the disclosed embodiments.” AK Steel Corp., 344
F.3d at 1244. Similarly, enablement does not require an inven-
tor to foresee future improvements on the patent—improve-
ments that in principle remain separately patentable and do
not undermine the original enablement. 37 C.F.R. § 1.75(e); see
Kevin E. Collins, Enabling After-Arising Technology, 34 J. C ORP.
L. 1083, 1099 (2009). A broad independent claim can be suffi-
ciently enabled without explicitly providing for every possi-
ble variant or sub-set that may appear in a dependent claim.
The Federal Circuit has indicated that for purposes of en-
ablement, independent and dependent claims must live or die
together. In Alcon Research, Ltd. v. Apotex Inc., the patent

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28 No. 17-1873
holder argued that its independent claim could survive a chal-
lenge based on obviousness, as long as the court narrowed the
scope of the independent claim so as not to include the full
scope of one of the dependent claims. 687 F.3d at 1368. The
court responded:
“This is not how patent law works. When you claim a
concentration range [in a dependent claim] you can’t
simply disavow the invalid portion and keep the valid
portion of the claim. If [part of the dependent claim] is ad-
mittedly not enabled, then the entire claim is invalid. …
Courts do not rewrite the claims to narrow them for
the patentee to cover only the valid portion. [Patent
holders] cannot have it both ways. Because [the de-
pendent claim] sets forth a concentration range, that
range at a minimum must be included in [the inde-
pendent claim].”
Id. (emphasis added); see also Ex Parte Forstova, No. 1998-
0667, 2002 WL 32349992, *3 (B.P.A.I. Apr. 11, 2002) (internal
citations omitted) (“We first express our concern about the
anomalous situation confronting us where dependent claims
2–5 are rejected as being non-enabled while claim 1, the
independent claim from which these claims directly or
indirectly depend, is not rejected. It has long been held that a
claim must be enabled throughout its scope. As a matter of
logic, assuming claims 2–5 are proper dependent claims and
we see no reason why they are not, the examiner’s decision

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No. 17-1873 29
that claims 2–5 are non-enabled necessarily means that claim 1
is non-enabled.”)3
C. Enablement of the ‘987 Patent
In our case, the parties disputed both the proper construc-
tion of “sort strategy” and how Claim 2 should be understood
at the summary judgment stage. The district court identified
at least three possible sort strategies: “high purity,” “high re-
covery,” and “constant flow rate.” The court also found that
“the process of ‘selecting’ sperm cells based upon their classi-
fication at Step (e) of Claim 1 does not necessarily require the
application of a sort strategy.” From these insights, the district
court recognized that “the application of a sort strategy [is] a
more narrow method by which cells to be photo-damaged are
identified.” Thus, the district court interpreted Claim 2 as a
variant within the broad scope of activity patented by Claim
1. Importantly, Claim 1 does and must cover both A/B sorting
accomplished without a second-tier sorting strategy (i.e. ran-
dom sorting), and A/B sorting that includes a further refine-
ment (by purity, recovery, flow rate, or the like). The possibil-
ity that Claim 1 does not encompass particular sort strategies
was rejected by the district court as a matter of law. Similar
cases decided by the Federal Circuit illustrate this pattern of
3 We need to say a word here about the citation to Forstova. The
Westlaw version omits about half of this quote, replacing it with “??”. We
have added the citation to the slip opinion on the U.S. Patent and Trade-
mark Office’s website, which provides the full text. The full version can
also be found in Jeffrey A. Lefstin, “The Formal Structure of Patent Law
and the Limits of Enablement,” 23 Berkely Tech. L. J. 1141, 1171 (2008).

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30 No. 17-1873
a broader independent claim and the need for the independ-
ent claim to enable all of the narrower dependent variants.
In Sitrick v. Dreamworks, LLC, 516 F.3d 993 (Fed. Cir. 2008),
a patent claimed technology for “integrating a user’s audio
signal or visual image into a pre-existing video game or
movie.” Id. at 995. The Federal Circuit found that “[b]ecause
the asserted claims are broad enough to cover both movies
and video games, the patents must enable both embodi-
ments.” Id. at 1000; see also Auto. Techs. Int’l v. BMW of N. Am.,
Inc., 501 F.3d 1274, 1285 (Fed. Cir. 2007) (finding that because
the claim includes “both mechanical and electronic side im-
pact sensors,” both must be enabled); Liebel-Flarsheim Co. v.
Medrad, Inc., 481 F.3d 1371, 1380 (Fed. Cir. 2007) (finding that
for claimed invention including “an injector system with and
without a pressure jacket,” the specification must enable
“both injector systems with and without a pressure jacket”).
The district court was aware of these cases, but it thought
that they could be distinguished. It wrote that “Sitrick stands
for the proposition that all embodiments of a particular claim
must be enabled, not that a nonenabled, dependent claim ren-
ders an enabled independent claim invalid as well.” But this
reasoning fails to take into account the fact that a dependent
claim, by definition, is one embodiment of the independent
claim on which it relies. Nazomi Commc’ns, Inc. v. Arm Hold-
ings, PLC, 403 F.3d 1364, 1370 (Fed. Cir. 2005) (noting that de-
pendent “[c]laim 3 describes an embodiment” but that
“[c]laim differentiation suggests that different embodiments,
reflecting the broader wording of [independent] claim 1, are
also permissible”).
The district court had already decided that Claim 1 is
broad enough to support a dependent Claim 2. Claim 1 covers

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No. 17-1873 31
a photo-damage sperm sorter that sorts cells based upon their
classification for characteristic A or B, whether or not a sec-
ondary sort strategy (for purity, recovery, speed, or some-
thing else) is used. Claim 2 covers a photo-damage sperm
sorter that sorts cells first based upon the A/B classification
and then pursuant to a particular sort strategy. If, as Sexing
Tech contends, the jury impliedly found that dependent
Claim 2 was not enabled, then it follows that the full scope of
Claim 1 was not enabled and it would fail for that reason. In
short, for purposes of enablement, once Claim 1 is enabled,
dependent Claim 2 must be also.
An example involving simpler technology may help. At
oral argument, counsel for Sexing Tech proposed a hypothet-
ical patent for a recliner. The independent claim comprises (1)
a headrest, (2) a reclining mechanism, and (3) a footrest. The
dependent claim adds an additional limitation to the third
limitation: the footrest must be adjustable. This is a proper
limitation; it narrows the type of footrest to an adjustable one.
A later recliner with a fixed footrest would infringe the inde-
pendent claim but not the dependent claim. Counsel for Sex-
ing Tech then argued that if the patent failed to teach how to
make the footrest adjustable, the dependent claim would be
invalid for enablement but the independent claim would not.
But Sexing Tech is describing an independent claim that is
not fully enabled and thus invalid. The independent claim
would have to cover both fixed and adjustable footrests, and
enablement must exist for the full scope of the patent—in this
case, all types of footrests. If the specification failed to enable
an adjustable foot in the dependent claim, then (as Alcon Re-
search, supra, indicated) the full scope of the invention is also

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32 No. 17-1873
not enabled in the independent claim, and both claims are in-
valid for non-enablement. See Sitrick, 516 F.3d at 1000.
This result ensures that the inventor of the recliner does
not reap broader exclusive rights than she has earned. Cf. Uni-
versal Oil Prods. Co. v. Globe Oil & Refining Co., 322 U.S. 471,
483–84 (1944) (finding that the claim must be limited to what
was enabled because “the quid pro quo is disclosure of a pro-
cess or device in sufficient detail to enable one skilled in the
art to practice the invention once the period of the monopoly
has expired”). This result is not unduly harsh, because inven-
tors who overreach and claim overbroad independent claims
may fall back on whatever dependent claims remain valid. A
separate dependent claim limiting “footrest” to “fixed foot-
rest” would remain valid, even if the independent claim fails
for lack of enablement of the adjustable option. The inventor
would be left with patent protection commensurate with the
scope of her enabling disclosure.
D. Written Description
Sexing Tech finally points to Professor Donald Chisum’s
statement that “[a] dependent claim may not be patentable,
despite the allowability of the independent claim, because of
the absence of support in the specification for the added limi-
tation.” 3 C HISUM, § 8.06[5][c]. But as one can see from his ci-
tation to section 7.04[3] of the treatise, which discusses only
the written-description requirement, Chisum is speaking here
about the latter requirement, not enablement. Id. Of the two
cases cited by Sexing Tech, one addresses only written de-
scription. See TurboCare Div. of Demag Delaval Turbomach. Corp.
v. General Elec. Co., 264 F.3d 1111, 1115–16, 1126 (Fed. Cir.
2011). The second case noted in dicta that dependent claims
“raise additional written description and enablement issues,”

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No. 17-1873 33
but the court found no such problems. Chiron Corp. v. Genen-
tech, Inc., 268 F. Supp. 2d 1148, 1166–67 (E.D. Cal. 2002). Nei-
ther case squarely raises the issue whether a dependent claim
could create an independent enablement issue, rather than an
independent written description issue.
The written description and enablement criteria operate
differently and serve different interests. Ariad Pharm., Inc. v.
Eli Lilly & Co., 598 F.3d 1336, 1345 (Fed. Cir. 2010) (en banc).
Section 112 of the Act requires that “[t]he specification shall
contain a written description of the invention,” 35 U.S.C.
§ 112(a), and then it calls for disclosure of the manner and pro-
cess of making and using the invention, id. (emphasis added).
Enablement protects the public’s right to benefit from the pa-
tented invention after the patent expires, while the written de-
scription requirement focuses on the nature and scope of the
claimed invention. Martin v. Mayer, 823 F.2d 500, 504–05 (Fed.
Cir. 1987), recognized as superseded by rule on other grounds by
Kubota v. Shibuya, 999 F.2d 517, 521 (Fed. Cir. 1993) (“Section
112 does not require that the specification contain that which
is known to those skilled in the art. But it does require speci-
ficity as to the claim limitations … .”) (citation omitted).
For our purposes, the crucial difference between these two
requirements is that the specification need not feature a writ-
ten description of every specific variant within the scope of
the claim. For example, “every species in a genus need not be
described in order that a genus meet the written description
requirement.” AbbVie Deutschland GmbH & Co. v. Janssen Bio-
tech, Inc., 759 F.3d 1285, 1301 (Fed. Cir. 2014) (quoting Regents
of the Univ. of Cal. v. Eli Lilly & Co., 119 F.3d 1559, 1568 (Fed.
Cir. 1997)) (alterations omitted). Indeed, it would make little

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34 No. 17-1873
sense for a written description requirement explicitly to in-
clude every possible iteration of the broader invention. To do
so would encourage patentholders to write out potentially in-
finite possibilities. Unlike enablement, where gaps in the
specification can be filled by the knowledge of a skilled arti-
san, the written-description requirement is held to the letter
and is satisfied only if a skilled artisan reading the application
would understand that a given limitation is at issue. “[C]on-
sider the case where the specification discusses only Com-
pound A and contains no broadening language of any kind.
This might very well enable one skilled in the art to make and
use Compounds B and C; yet the class consisting of A, B and
C has not been described.” In re DiLeone, 436 F.2d 1404, 1405
n.1 (C.C.P.A. 1971). Thus, the descriptions for dependent
claims may be inadequate even if the description of the inde-
pendent claim is fine. Indeed, dependent claims may be more
likely than independent claims to fail the written description
requirement simply because they feature more limitations.
More limitations make for a heavier burden on the written
description requirement, but they lessen the burden for ena-
blement. Ex Parte Grasselli, 231 U.S.P.Q. 393, 1983 WL 51855 *2
(P.T.O. Bd. App. 1983) (finding that “the negative limitations
recited in the present claims, which did not appear in the
specification as filed, introduce new concepts and violate the
[written] description requirement” despite the Board’s state-
ment that it found no problem with lack of enablement). Lim-
itations narrow the scope of the claim, and so there is less to
be enabled. Although it is certainly possible for a dependent
claim to be more enabled than the independent variant, it is
impossible for it to be less so. Martek Biosciences Corp. v. Nutri-
nova, Inc., 579 F.3d 1363, 1377–78 (Fed. Cir. 2009) (enablement

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No. 17-1873 35
evidence supporting dependent claims was stronger than ev-
idence for independent claim because dependent claims’ nar-
rower set of possibilities was discoverable with reasonable ex-
perimentation, while broader independent claim was not).
Applying these principles to our case, we conclude that
the jury’s verdicts were irreconcilable. A proper dependent
claim cannot fail for lack of enablement while its independent
claim stands, because the dependent claim’s scope is a subset
of the independent claim’s scope. The full scope of Claim 1 of
the ‘987 patent cannot have been enabled at the same time as
the full scope of Claim 2 was not. With enablement and obvi-
ousness eliminated as possible explanations, there is no plau-
sible explanation for the jury’s verdict, and a new trial is nec-
essary on this aspect of the case.
VI. Confidentiality Agreement
Finally, we step away from the world of patent law and
back to more familiar territory: breach of contract. The con-
tract at issue is the “Semen Sorting Agreement,” which is the
main document governing the relationship between ABS and
Sexing Tech. The jury found that ABS breached the confiden-
tiality commitment in this agreement when Kathy Mean, a
former employee of XY (recall that XY is a subsidiary of Sex-
ing Tech), brought trade secrets with her to ABS. ABS con-
cedes the theft but argues that the stolen trade secrets cannot
give rise to a breach of contract because the agreement cov-
ered only information “provided by Sexing Tech.” The district
court disagreed and denied ABS’s motion for judgment as a
matter of law, finding that the contract was ambiguous on this
point. We review the district court’s interpretation of the con-
tract de novo. BKCAP, LLC v. CAPTEC Franchise Trust 2000-1,
572 F.3d 353, 358 (7th Cir. 2009).

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36 No. 17-1873
The question for us is simple: could “Sexing Tech’s Confi-
dential Information,” as defined by the Semen Sorting Agree-
ment, reasonably include information stolen by a former em-
ployee of a Sexing Tech subsidiary? Under Texas law—which
the parties agree governs this contract—“[a]n ambiguity does
not arise simply because the parties offer conflicting interpre-
tations.” Am. Mfg. Mut. Ins. Co. v. Schaefer, 124 S.W. 3d 154,
157 (Tex. 2003). It exists “only if the contract language is sus-
ceptible to two or more reasonable interpretations.” Id. at 157.
Extrinsic evidence, however, cannot create ambiguity where
it does not exist. Nat’l Union Fire Ins. Co. of Pittsburgh v. CBI
Indus., Inc., 907 S.W.2d 517, 520 (Tex. 1995). Texas courts read
contracts as a whole. See id. The provision in question reads
as follows:
As used herein, the term “ST’s Confidential Infor-
mation” shall mean (i) that information pertaining to
the research, processing or production of Sorted Semen
that is disclosed by ST or its Affiliates to ABS and is
confidential, non-public, proprietary and/or generally
not known to the public, to include but not limited to:
any and all information relating to technology, meth-
ods, techniques, processes, know-how, concepts, se-
crets, and scientific or technical know-how, whether
such information be tangible, intellectual or otherwise;
and (ii) any information related to Sorted Semen that is
based on or derived from any of the foregoing,
whether by ABS or ST or third parties. ST’s Confiden-
tial Information shall encompass all of the foregoing
information whether provided by ST in writing, orally
or by other means. ABS agrees that as a recipient of
ST’s Confidential Information, ABS shall not use, dis-
close, or make available ST’s Confidential Information

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No. 17-1873 37
to any third party, except for those representatives of
ABS that have an actual need to know such ST’s Con-
fidential Information in connection with the perfor-
mance of this Agreement. The foregoing confidential-
ity obligations shall continue for ten (10) years from the
expiration or termination of this Agreement.
ABS says that the provision limits “ST’s Confidential Infor-
mation” to information “provided by” or “disclosed by” Sex-
ing Tech. Sexing Tech responds that subsection (ii) of the
agreement brings information not provided directly by Sex-
ing Tech within the meaning of “Confidential Information,”
or at least creates enough ambiguity to send the issue to the
jury.
The language of this provision is broad: it encompasses in-
formation disclosed either by Sexing Tech itself or its affiliates.
It also covers all methods of providing information, whether
in writing, orally, or “by other means.” This language com-
fortably includes Means’s actions. Nothing indicates that she
had a source other than Sexing Tech for the information she
conveyed. She simply funneled that information from Sexing
Tech to ABS. The jury’s finding that this amounted to a breach
by ABS of the confidentiality agreement thus rested on a
proper understanding of the contract language.
VII. Conclusion
The district court’s decision denying ABS’s motion for
judgment as a matter of law on the ground that the ’987 patent
fails for obviousness is A FFIRMED . We also AFFIRM the court’s
denial of ABS’s motion for judgment as a matter of law on the
breach of the confidentiality agreement. We conclude that the
jury’s verdicts with respect to the enablement of Claims 1 and

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38 No. 17-1873
2 are irreconcilably inconsistent. We therefore R EVERSE the de-
nial of ABS’s motion for a new trial on the ’987 patent and
R EMAND for further proceedings consistent with this opinion.
Each side will bear its own costs on appeal.

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No. 17-1873 39
APPENDIX
U.S. Patent No. 8,206,987 B2
PHOTO-DAMAGE METHOD FOR SORTING PARTICLES
[Claims 1, 2, and 7]
***
What is claimed is:
1. A method of sorting a mixture of stained sperm
cells having either characteristic A or characteristic B into
at least one population, the method comprising the steps
of:
a. flowing a fluid stream containing stained sperm
cells through a flow path at a fluid delivery rate;
b. exciting fluorescence emissions from the stained
sperm cells having characteristic A and the stained
sperm cells having characteristic B flowing in the
flow path;
c. detecting the fluorescence emissions from the ex-
cited sperm cells;
d. classifying the stained sperm cells as either having
characteristic A or having characteristic B based
upon the fluorescence emissions;
e. selecting stained sperm cells in the flow path based
on their classification; and
f. photo-damaging the selected sperm cells to pro-
duce an enriched population of sperm with respect
to either characteristic A or characteristic B.

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40 No. 17-1873
2. A method of sorting a mixture of stained sperm
cells according to claim 1 wherein the step of selecting
stained sperm cells in the flow path to photo-damage fur-
ther comprises the step of photo-damaging sperm cells
based upon a sort strategy.
***
7. A method of sorting a mixture of stained sperm cells
according to claim 1 wherein characteristic A is indicative
of a live X-chromosome bearing sperm cell (X) and
wherein characteristic B is indicative of something other
than a live X-chromosome bearing sperm cell (–X).

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