Department of Commerce
                          Patent and Trademark Office

                        [Docket No. 970129014-7014-01]

                                 RIN 0651-XX09

           Interim Guidelines for the Examination of Claims Directed
           to Species of Chemical Compositions Based Upon a Single
                              Prior Art Reference

Agency: Patent and Trademark Office, Commerce.
Action: Notice.
Summary: The Patent and Trademark Office (PTO) requests comments from
any interested member of the public on interim guidelines to be used by
office personnel in their review of patent applications which contain
claims directed to a species or subgenus of chemical compositions for
compliance with 35 U.S.C.    103 based upon a single prior art reference
which discloses a genus embracing the claimed species or subgenus but
does not expressly describe the particular claimed species or subgenus.
Dates: The interim guidelines are effective February 11, 1997.
   Written comments on the interim guidelines will be accepted by the
PTO until April 14, 1997.
Addresses: Written comments should be addressed to the attention of
Linda Moncys Isacson, Office of the Solicitor, P.O. Box 15667,
Arlington, Virginia 22215 or to Linda S. Therkorn, Box Comments,
Assistant Commissioner for Patents, Washington, D.C. 20231, or by
facsimile transmission to (703) 305-9373 or by electronic mail to
baird-comments@uspto.gov.
   Written comments will be made available for public inspection at the
Patent Search Room, Crystal Plaza 3, 2021 South Clark Place, Arlington,
Va. In addition, comments provided in machine-readable format will be
available through the PTO's Website at http://www.uspto.gov.
For Further Information Contact: Linda Moncys Isacson, Office of the
Solicitor, P.O. Box 15667, Arlington, Virginia 22215 or Linda S.
Therkorn, Box Comments, Assistant Commissioner for Patents, Washington,
D.C. 20231, or by facsimile transmission to (703) 305-9373 or by
electronic mail to baird-comments@uspto.gov.
Supplementary Information: The Commissioner of Patents and Trademarks
issued a Notice in the Official Gazette (O.G.) on April 17, 1995 (1174
O.G. 68), withdrawing the Office's March 22, 1994 O.G. Notice (1161 O.G.
314). Both notices were entitled "In re Baird." Pursuant to the April
17, 1995 O.G. Notice, the following interim examination guidelines are
being published for public comment. The purpose of these guidelines is
to assist PTO personnel in the examination of applications which contain
claims directed to a species or subgenus of chemical compositions for
compliance with 35 U.S.C.    103 based upon a single prior art reference
which discloses a genus embracing the claimed species or subgenus but
does not expressly describe the particular claimed species or subgenus.
Therefore, these interim guidelines will be referred to as
"Genus-Species Guidelines."
   It has been determined that these interim guidelines are not a
significant rule for purposes of Executive Order 12866. Because these
guidelines govern internal practices, they are exempt from notice and
comment rulemaking under 5 U.S.C.    553(b)(A).
   Members of the public may present written comments on these
guidelines. Written comments should include the following information:

--Name and affiliation of the individual responding;
--An indication of whether the comments offered represent views of
  the respondent's organization or are the respondent's personal views; and
--If applicable, information on the respondent's organization,
  including the type of organization (e.g., business, trade group,
  university, nonprofit organization).

   The PTO is particularly interested in comments relating to the
accuracy of the emphasized prior art teachings, and comments identifying
any additional teachings that should be emphasized in determining
whether a prima facie case of obviousness exists in the types of cases
covered by these interim guidelines. The PTO is also interested in
comments relating to the effect these guidelines may have on future
application submissions.

February 5, 1997                                            BRUCE A. LEHMAN
                                        Assistant Secretary of Commerce and
                                     Commissioner of Patents and Trademarks


I. Interim Guidelines for the Examination of Claims Directed to Species
of Chemical Compositions Based Upon a Single Prior Art Reference

   These "Genus-Species Guidelines" are to assist Office personnel in
the examination of applications which contain claims to species or a
subgenus of chemical compositions for compliance with 35 U.S.C.    103
based upon a single prior art reference which discloses a genus
encompassing the claimed species or subgenus but does not expressly
disclose the particular claimed species or subgenus. Office personnel
should attempt to find additional prior art to show that the differences
between the prior art primary reference and the claimed invention as a
whole would have been obvious. Where such additional prior art is not
found, Office personnel should follow these guidelines to determine
whether a single reference 35 U.S.C.    103 rejection would be
appropriate. The guidelines are based on the Office's current
understanding of the law and are believed to be fully consistent with
binding precedent of the Supreme Court, the Federal Circuit, and the
Federal Circuit's predecessor courts.
   The analysis of the guidelines begins at the point during examination
after a single prior art reference is found disclosing a genus
encompassing the claimed species or subgenus. Before reaching this
point, Office personnel should follow normal examination procedures.
Accordingly, Office personnel should first analyze the claims as a whole
in light of and consistent with the written description, considering all
claim limitations.1 Next, Office personnel should conduct a thorough
search of the prior art and identify all relevant references.2 If the
most relevant prior art consists of a single prior art reference
disclosing a genus encompassing the claimed species or subgenus, Office
personnel should follow the guidelines set forth herein.
   These guidelines do not constitute substantive rulemaking and hence
do not have the force and effect of law. Rather, they are to assist
Office personnel in analyzing claimed subject matter for compliance with
substantive law. Thus, rejections must be based upon the substantive
law, and it is these rejections which are appealable, not any failure by
Office personnel to follow these guidelines.
   Office personnel are to rely on these guidelines in the event of any
inconsistent treatment of issues between these guidelines and any
earlier provided guidance from the Office.

II. Determine Whether the Claimed Species or Subgenus Would Have Been
Obvious to One of Ordinary Skill in the Pertinent Art at the Time the
Invention Was Made

   The patentability of a claim to a specific compound or subgenus embraced
by a prior art genus should be analyzed no differently than any other
claim for purposes of 35 U.S.C.    103.3 A determination of
patentability under 35 U.S.C.    103 should be made upon the facts of
the particular case in view of the totality of the circumstances.4 Use
of per se rules by Office personnel is improper for determining whether
claimed subject matter would have been obvious under 35 U.S.C.    103.5
The fact that a claimed species or subgenus is encompassed by a prior
art genus is not sufficient by itself to establish a prima facie case of
obviousness.6
   A proper obviousness analysis involves a three-step process. First,
Office personnel should establish a prima facie case of unpatentability
considering the factors set out by the Supreme Court in Graham v. John
Deere.7 If a prima facie case is established, the burden shifts to
applicant to come forward with rebuttal evidence or argument to overcome
the prima facie case.8 Finally, Office personnel should evaluate the
totality of the facts and all of the evidence to determine whether they
still support a conclusion that the claimed invention would have been
obvious to one of ordinary skill in the art at the time the invention
was made.9

   A. Establishing a Prima Facie Case of Obviousness

   To establish a prima facie case of obviousness in a genus-species
chemical composition situation, as in any other 35 U.S.C.    103 case,
it is essential that Office personnel find some motivation or suggestion
to make the claimed invention in light of the prior art teachings.10 In
order to find such motivation or suggestion there should be a reasonable
likelihood that the claimed invention would have the properties
disclosed by the prior art teachings.11 These disclosed findings should
be made with a complete understanding of the first three "Graham
factors."12  Thus, Office personnel should (1) determine the "scope and
content of the prior art"; (2) ascertain the "differences between the
prior art and the claims at issue"; and (3) determine "the level of
ordinary skill in the pertinent art."13

   1. Determine The Scope and Content of the Prior Art

   As an initial matter, Office personnel should determine the scope and
content of the relevant prior art. Each reference must qualify as prior
art under 35 U.S.C.    102,14 and should be in the field of applicant's
endeavor, or be reasonably pertinent to the particular problem with
which the inventor was concerned.15
   In the case of a prior art reference disclosing a genus, Office
personnel should make findings as to (1) the structure of the disclosed
prior art genus and that of any expressly described species or subgenus
within the genus; (2) any physical or chemical properties and utilities
disclosed for the genus, as well as any suggested limitations on the
usefulness of the genus, and any problems alleged to be addressed by the
genus; (3) the predictability of the technology; and (4) the number of
species encompassed by the genus taking into consideration all of the
variables possible.

   2. Ascertain The Differences Between the Prior Art Genus and the Claimed
Species or Subgenus

   Once a relevant prior art genus is identified, Office personnel should
compare it to the claimed species or subgenus to determine the
differences. Through this comparison, the closest disclosed species or
subgenus in the prior art reference should be identified and compared to
that claimed. Office personnel should make explicit findings on the
similarities and differences between the closest prior art reference and
the claimed species or subgenus including findings relating to
similarity of structure, chemical properties and utilities.16

   3. Determine the Level of Skill in the Art

   Office personnel should evaluate the prior art from the standpoint of
the hypothetical person having ordinary skill in the art at the time the
claimed invention was made.17 In most cases, the only facts of record
pertaining to the level of skill in the art will be found within the
prior art reference. However, any additional evidence presented by
applicant should be evaluated.

   4. Determine Whether One of Ordinary Skill in the Art Would Have Been
Motivated to Select the Claimed Species or Subgenus

   In light of the findings made relating to the three Graham factors,
Office personnel should determine whether one of ordinary skill in the
relevant art would have been motivated to make the claimed invention as
a whole, i.e., to select the claimed species or subgenus from the
disclosed prior art genus.18 To address this key issue, Office personnel
should consider all relevant prior art teachings, focusing on the
following, where present.

   a. Consider the Size of the Genus

   Consider the size of the prior art genus, bearing in mind that size
alone cannot support an obviousness rejection.19 There is no absolute
correlation between the size of the prior art genus and a conclusion of
obviousness.20 Thus, the mere fact that a prior art genus contains a
small number of members does not create a per se rule of obviousness.
Some motivation to select the claimed species or subgenus must be taught
by the prior art.21 However, a genus may be so small that it would
anticipate the claimed species or subgenus. For example, it has been
held that a prior art genus containing only 20 compounds inherently
anticipated a claimed species within the genus because "one skilled in
[the] art would . . . envisage each member" of the genus.22

   b. Consider the Express Teachings

   If the prior art reference expressly teaches a particular reason to
select the claimed species or subgenus, Office personnel should point
out the express disclosure which would have motivated one of ordinary
skill in the art to select the claimed invention.23

   c. Consider the Teachings of Structural Similarity

   Consider any teachings of a "typical," "preferred," or "optimum" species
or subgenus within the disclosed genus. If such a species or subgenus is
structurally similar to that claimed, its disclosure may motivate one of
ordinary skill in the art to choose the claimed species or subgenus from
the genus,24 based on the reasonable expectation that structurally
similar species usually have similar properties.25 The utility of such
properties will normally provide some motivation to make the claimed
species or subgenus.26
   In making an obviousness determination, Office personnel should
consider the number of variables which must be selected or modified, and
the nature and significance of the differences between the prior art and
the claimed invention.27 The closer the physical and chemical
similarities between the claimed species or subgenus and any exemplary
species or subgenus disclosed in the prior art, the greater the
expectation that the claimed subject matter will function in an
equivalent manner to the genus.28
   Similarly, consider any teaching or suggestion in the reference of a
preferred species or subgenus that is significantly different in
structure from the claimed species or subgenus. Such a teaching may
weigh against selecting the claimed species or subgenus and thus against
a determination of obviousness.29 For example, teachings of preferred
species of a complex nature within a disclosed genus may motivate an
artisan of ordinary skill to make similar complex species and thus teach
away from making simple species within the genus.30 Concepts used to
analyze the structural similarity of chemical compounds in other types
of chemical cases are equally useful in analyzing genus-species cases.31
Generally, some teaching of a structural similarity will be necessary to
suggest selection of the claimed species or subgenus.32

   d. Consider the Teachings of Similar Properties or Uses

   Consider the properties and utilities of the structurally similar prior
art species or subgenus. It is the properties and utilities that provide
real world motivation for a person of ordinary skill to make species
structurally similar to those in the prior art.33 Conversely, lack of
any known useful properties weighs against a finding of motivation to
make or select a species or subgenus.34 However, the prior art need not
disclose a newly discovered property in order for there to be a prima
facie case of obviousness.35 If the claimed invention and the
structurally similar prior art species share a useful property, that
will generally be sufficient to motivate an artisan of ordinary skill to
make the claimed species.36 For example, based on a finding that a
tri-orthoester and a tetra-orthoester behave similarly in certain
chemical reactions, it has been held that one of ordinary skill in the
relevant art would have been motivated to select either structure.37 In
fact, similar properties may normally be presumed when compounds are
very close in structure.38 Thus, evidence of similar properties weighs
in favor of a conclusion that the claimed invention would have been
obvious.39

   e. Consider the Predictability of the Technology

   Consider the predictability of the technology.40 If the technology is
unpredictable, it is less likely that structurally similar species will
render a claimed species obvious because it may not be reasonable to
infer that they would share similar properties.41 However, obviousness
does not require absolute predictability, only a reasonable expectation
of success, i.e., a reasonable expectation of obtaining similar
properties.42

   f. Consider Any Other Teaching to Support the Selection of the Species
or Subgenus

   The categories of relevant teachings enumerated above are those most
frequently encountered in a genus-species case, but they are not
exclusive. Office personnel should consider the totality of the evidence
in each case. In unusual cases, there may be other relevant teachings
sufficient to support the selection of the species or subgenus and,
therefore, a conclusion of obviousness.

   5. Make Express Fact-Findings And Determine Whether They Support A Prima
Facie Case of Obviousness

   Based on the evidence as a whole,43 Office personnel should make express
fact-findings relating to the Graham factors, focusing primarily on the
prior art teachings discussed above. The fact-findings should
specifically articulate what teachings or suggestions in the prior art
would have motivated one of ordinary skill in the art to select the
claimed species or subgenus.44 Thereafter, it should be determined
whether these findings, considered as a whole, support a prima facie
case that the claimed invention would have been obvious to one of
ordinary skill in the relevant art at the time the invention was made.

   B. Determining Whether Rebuttal Evidence Is Sufficient To Overcome the
Prima Facie Case of Obviousness

   If a prima facie case of obviousness is established, the burden shifts
to the applicant to come forward with arguments and/or evidence to rebut
the prima facie case.45 Rebuttal evidence and arguments can be presented
in the specification,46 by counsel,47 or by way of an affidavit or
declaration under 37 CFR 1.132.48 However, arguments of counsel cannot
take the place of factually supported objective evidence.49 Office
personnel should consider all rebuttal arguments and evidence presented
by applicants.50 Rebuttal evidence may include evidence of "secondary
considerations," such as "commercial success, long felt but unsolved
needs, [and] failure of others,"51 evidence that the claimed invention
yields unexpectedly improved properties or properties not present in the
prior art,52 or evidence that the claimed invention was copied by
others.53 It may also include evidence of the state of the art, the
level of skill in the art, and the beliefs of those skilled in the art.54
   Consideration of rebuttal evidence and arguments requires Office
personnel to weigh the proffered evidence and arguments. Office
personnel should avoid giving evidence no weight, except in rare
circumstances.55 However, to be entitled to substantial weight, the
applicant should establish a nexus between the rebuttal evidence and the
claimed invention,56 i.e., objective evidence of nonobviousness must be
attributable to the claimed invention.57 Additionally, the evidence must
be reasonably commensurate in scope with the claimed invention.58
However, an exemplary showing may be sufficient to establish a
reasonable correlation between the showing and the entire scope of the
claim, when viewed by a skilled artisan.59 On the other hand, evidence
of an unexpected property may not be sufficient regardless of the scope
of the showing.60 Accordingly, each case should be evaluated
individually based on the totality of the circumstances.
   Office personnel should not evaluate rebuttal evidence for its
"knockdown" value against the prima facie case61 or summarily dismiss it
as not compelling or insufficient. If the evidence is deemed
insufficient to rebut the prima facie case of obviousness, Office
personnel should specifically set forth the facts and reasoning that
justify this conclusion.

III. Reconsider All Evidence and Clearly Communicate Findings and
Conclusions

   A determination under 35 U.S.C.    103 should rest on all the evidence
and should not be influenced by any earlier conclusion.62 Thus, once the
applicant has presented rebuttal evidence, Office personnel should
reconsider any initial obviousness determination in view of the entire
record.63 All the proposed rejections and their bases should be reviewed
to confirm their correctness. Only then should any rejection be imposed
in an Office action. The Office action should clearly communicate the
Office's findings and conclusions, articulating how the conclusions are
supported by the findings.
   Where applicable, the findings should clearly articulate which
portions of the reference support any rejection. Explicit findings on
motivation or suggestion to select the claimed invention should also be
articulated in order to support a 35 U.S.C.    103 ground of
rejection.64 Conclusory statements of similarity or motivation, without
any articulated rationale or evidentiary support, do not constitute
sufficient factual findings.

VI. Notes

   1. When evaluating the scope of a claim, every limitation in the claim
must be considered. E.g., In re Ochiai, 71 F.3d 1565, 1572, 37 USPQ2d
1127, 1133 (Fed. Cir. 1995). However, the claimed invention may not be
dissected into discrete elements to be analyzed in isolation, but must
be considered as a whole. E.g., W.L. Gore & Assoc., Inc. v. Garlock,
Inc., 721 F.2d 1540, 1548, 220 USPQ 303, 309 (Fed. Cir. 1983), cert.
denied, 469 U.S. 851 (1984); Jones v. Hardy, 727 F.2d 1524, 1530, 220
USPQ 1021, 1026 (Fed. Cir. 1983) ("treating the advantage as the
invention disregards the statutory requirement that the invention be
viewed `as a whole'").

   2. Both claimed and unclaimed aspects of the invention should be
searched if there is a reasonable expectation that the unclaimed aspects
may be later claimed.

   3. "The section 103 requirement of unobviousness is no different in
chemical cases than with respect to other categories of patentable
inventions." In re Papesch, 315 F.2d 381, 385, 137 USPQ 43, 47 (CCPA
1963).

   4. E.g., In re Dillon, 919 F.2d 688, 692-93, 16 USPQ2d 1897, 1901 (Fed.
Cir. 1990) (in banc), cert. denied, 500 U.S. 904 (1991).

   5. E.g., In re Brouwer, 77 F.3d 422, 425, 37 USPQ2d 1663, 1666 (Fed.
Cir. 1996); In re Ochiai, 71 F.3d 1565, 1572, 37 USPQ2d 1127, 1133 (Fed.
Cir. 1995); In re Baird, 16 F.3d 380, 382, 29 USPQ2d 1550, 1552 (Fed.
Cir. 1994).

   6. In re Baird, 16 F.3d 380, 382, 29 USPQ2d 1550, 1552 (Fed. Cir. 1994)
("The fact that a claimed compound may be encompassed by a disclosed
generic formula does not by itself render that compound obvious."); In
re Jones, 958 F.2d 347, 350 21 USPQ2d 1941; 1943 (Fed. Cir. 1992)
(Federal Circuit has "decline[d] to extract from Merck [& Co. v.
Biocraft Laboratories Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.
1989)] the rule that regardless of how broad, a disclosure of a chemical
genus renders obvious any species that happens to fall within it."). See
also In re Deuel, 51 F.3d 1552, 1559, 34 USPQ2d 1210, 1215 (Fed. Cir.
1995).

   7. E.g., In re Bell, 991 F.2d 781, 783, 26 USPQ2d 1529, 1531 (Fed. Cir.
1993) ("The PTO bears the burden of establishing a case of prima facie
obviousness."); In re Rijckaert, 9 F.3d 1531, 1532, 28 USPQ2d 1955, 1956
(Fed. Cir. 1993); In re Oetiker, 977 F.2d 1443, 1445, 24 USPQ2d 1443,
1444 (Fed. Cir. 1992).

   Graham v. John Deere Co., 383 U.S. 1, 17-18 (1966), requires that to
make out a case of obviousness, one must: (1) determine the scope and
contents of the prior art; (2) ascertain the differences between the
prior art and the claims in issue; (3) determine the level of skill in
the pertinent art; and (4) evaluate any evidence of secondary
considerations.

   8. E.g., Bell, 991 F.2d at 783-84, 26 USPQ2d at 1531; Rijckaert, 9 F.3d
at 1532, 28 USPQ2d at 1956; Oetiker, 977 F.2d at 1445, 24 USPQ2d at 1444.

   9. Id.

   10. E.g., In re Brouwer, 77 F.3d 422, 425, 37 USPQ2d 1663, 1666 (Fed.
Cir. 1996)("[T]he mere possibility that one of the esters or the active
methylene group-containing compounds . . . could be modified or replaced
such that its use would lead to the specific sulfoalkylated resin
recited in claim 8 does not make the process recited in claim 8 obvious
`unless the prior art suggested the desirability of [such a]
modification' or replacement.") (quoting In re Gordon, 733 F.2d 900,
902, 221 USPQ 1125, 1127 (Fed. Cir. 1984); In re Vaeck, 947 F.2d 488,
493, 20 USPQ2d 1438, 1442 (Fed. Cir. 1991) ("[A] proper analysis under
  103 requires, inter alia, consideration of . . . whether the prior
art would have suggested to those of ordinary skill in the art that they
should make the claimed composition or device, or carry out the claimed
process.").

   11. The prior art disclosure may be express, implicit, or inherent.
Regardless of the type of disclosure, the prior art must provide some
motivation to one of ordinary skill in the art to make the claimed
invention in order to support a conclusion of obviousness. E.g., Vaeck,
947 F.2d at 493, 20 USPQ2d at 1442 (A proper obviousness analysis
requires consideration of "whether the prior art would also have
revealed that in so making or carrying out [the claimed invention],
those of ordinary skill would have a reasonable expectation of
success."); In re Dow Chemical Co., 837 F.2d 469, 473, 5 USPQ2d 1529,
1531 (Fed. Cir. 1988) ("The consistent criterion for determination of
obviousness is whether the prior art would have suggested to one of
ordinary skill in the art that this process should be carried out and
would have a reasonable likelihood of success, viewed in the light of
the prior art."); Hodosh v. Block Drug Co., 786 F.2d 1136, 1143 n.5, 229
USPQ 182, 187 n.5 (Fed. Cir.), cert. denied, 479 U.S. 827 (1986).

   12. When evidence of secondary considerations such as unexpected results
is initially before the Office, for example in the specification, that
evidence should be considered in deciding whether there is a prima facie
case of obviousness. The determination as to whether a prima facie case
exists should be made on the full record before the Office at the time
of the determination.

   13. Graham v. John Deere, 383 U.S. 1, 17, 148 USPQ 459, 467 (1966).
Accord, e.g., In re Paulsen, 30 F.3d 1475, 1482, 31 USPQ2d 1671, 1676
(Fed. Cir. 1994).

   14. E.g., Panduit Corp. v. Dennison Mfg. Co., 810 F.2d 1561, 1568, 1
USPQ2d 1593, 1597 (Fed. Cir.)("Before answering Graham's `content'
inquiry, it must be known whether a patent or publication is in the
prior art under 35 U.S.C.    102."), cert. denied, 481 U.S. 1052 (1987).

   15. In re Oetiker, 977 F.2d 1443, 1447, 24 USPQ2d 1443, 1445 (Fed. Cir.
1992). Accord, e.g., In re Clay, 966 F.2d 656, 658-59, 23 USPQ2d 1058,
1060 (Fed. Cir. 1992).

   16. In Stratoflex, Inc. v. Aeroquip Corp., 713 F.2d 1530, 1537, 218 USPQ
871, 877 (Fed. Cir. 1983), the Court noted that "the question under 35
U.S.C.    103 is not whether the differences [between the claimed
invention and the prior art] would have been obvious" but "whether the
claimed invention as a whole would have been obvious." (emphasis in
original).

   17. See, Ryko Manufacturing Co. v. Nu-Star Inc., 950 F.2d 714, 718, 21
USPQ2d 1053, 1057 (Fed. Cir. 1991) ("The importance of resolving the
level of ordinary skill in the art lies in the necessity of maintaining
objectivity in the obviousness inquiry."); Uniroyal Inc. v. Rudkin-Wiley
Corp., 837 F.2d 1044, 1050, 5 USPQ2d 1434, 1438 (Fed. Cir.), cert.
denied, 488 U.S. 825 (1988) (evidence must be viewed from position of
ordinary skill, not of an expert).

   18. E.g., Ochiai, 71 F.3d at 1569-70, 37 USPQ2d at 1131; Deuel, 51 F.3d
at 1557, 34 USPQ2d at 1214 ("[A] prima facie case of unpatentability
requires that the teachings of the prior art suggest the claimed
compounds to a person of ordinary skill in the art." (emphasis in
original)); Jones, 958 F.2d at 351, 21 USPQ2d at 1943-44 (Fed. Cir.
1992); Dillon, 919 F.2d at 692, 16 USPQ2d at 1901; In re Lalu, 747 F.2d
703, 705, 223 USPQ 1257, 1258 (Fed. Cir. 1984) ("The prior art must
provide one of ordinary skill in the art the motivation to make the
proposed molecular modifications needed to arrive at the claimed
compound."). See also In re Kemps, 97 F.3d 1427, 1430, 40 USPQ2d 1309,
1311 (Fed. Cir. 1996) (discussing motivation to combine).

   19. See, e.g., Baird, 16 F.3d at 383, 29 USPQ2d at 1552 (observing that
"it is not the mere number of compounds in this limited class which is
significant here but, rather, the total circumstances involved").

   20. Id.

   21. See, e.g., Deuel, 51 F.3d at 1558-59, 34 USPQ2d at 1215 ("No
particular one of these DNAs can be obvious unless there is something in
the prior art to lead to the particular DNA and indicate that it should
be prepared."); Baird, 16 F.3d at 382-83, 29 USPQ2d at 1552; Bell, 991
F.2d at 784, 26 USPQ2d at 1531 ("Absent anything in the cited prior art
suggesting which of the 1036 possible sequences suggested by
Rinderknecht corresponds to the IGF gene, the PTO has not met its burden
of establishing that the prior art would have suggested the claimed
sequences.").

   22. In re Petering, 301 F.2d 676, 681, 133 USPQ 275, 280 (CCPA
1962)(emphasis in original). Accord In re Schaumann, 572 F.2d 312, 316,
197 USPQ 5, 9 (CCPA 1978)(prior art genus encompassing claimed species
which disclosed preference for lower alkyl secondary amines and
properties possessed by the claimed compound constituted description of
claimed compound for purposes of 35 U.S.C.    102(b)). C.f., In re
Ruschig, 343 F.2d 965, 974, 145 USPQ 274, 282 (CCPA 1965)(Rejection of
claimed compound in light of prior art genus based on Petering is not
appropriate where the prior art does not disclose a small recognizable
class of compounds with common properties.).

   23. An express teaching may be based on a statement in the prior art
reference such as an art recognized equivalence. For example, see Merck
& Co. v. Biocraft Labs., 874 F.2d 804, 807, 10 USPQ2d 1843, 1846 (Fed.
Cir.), cert. denied, 493 U.S. 975 (1989)(holding claims directed to
diuretic compositions comprising a specific mixture of amiloride and
hydrochlorothiazide were obvious over a prior art reference expressly
teaching that amiloride was a pyrazinoylguanidine which could be
co-administered with potassium excreting diuretic agents, including
hydrochlorothiazide which was a named example, to produce a diuretic
with desirable sodium and potassium eliminating properties). See also,
In re Kemps, 97 F.3d 1427, 1430, 40 USPQ2d 1309, 1312 (Fed. Cir. 1996)
(holding there is sufficient motivation to combine teachings of prior
art to achieve claimed invention where one reference specifically refers
to the other).

   24. E.g., Dillon, 919 F.2d at 696, 16 USPQ2d at 1904. See also Deuel, 51
F.3d at 1558, 34 USPQ2d at 1214 ("Structural relationships may provide
the requisite motivation or suggestion to modify known compounds to
obtain new compounds. For example, a prior art compound may suggest its
homologs because homologs often have similar properties and therefore
chemists of ordinary skill would ordinarily contemplate making them to
try to obtain compounds with improved properties.").

   25. E.g., Dillon, 919 F.2d at 693, 16 USPQ2d at 1901.

   26. See id.

   27. E.g., In re Jones, 958 F.2d 347, 350, 21 USPQ2d 1941, 1943 (Fed.
Cir. 1992) (reversing obviousness rejection of novel dicamba salt with
acyclic structure over broad prior art genus encompassing claimed salt,
where disclosed examples of genus were dissimilar in structure, lacking
an ether linkage or being cyclic); In re Susi, 440 F.2d 442, 445, 169
USPQ423, 425 (CCPA 1971) (the difference from the particularly preferred
subgenus of the prior art was a hydroxyl group, a difference conceded by
applicant "to be of little importance.").

   In the area of biotechnology, an exemplified species may differ from a
claimed species by a conservative substitution ("the replacement in a
protein of one amino acid by another, chemically similar, amino acid . .
. [which] is generally expected to lead to either no change or only a
small change in the properties of the protein." Dictionary of
Biochemistry and Molecular Biology 97 (John Wiley & Sons, 2d ed. 1989)).
The effect of a conservative substitution on protein function depends on
the nature of the substitution and its location in the chain. Although
at some locations a conservative substitution may be benign, in some
proteinsonly one amino acid is allowed at a given position. For example,
the gain or loss of even one methyl group can destabilize the structure
if close packing is required in the interior of domains. James Darnell
et al., Molecular Cell Biology 51 (2d ed. 1990).

   28. E.g., Dillon, 919 F.2d at 696, 16 USPQ2d at 1904 (and cases cited
therein). C.f. Baird, 16 F.3d at 382-83, 29 USPQ2d at 1552 (disclosure
of dissimilar species can provide teaching away).

   29. Baird, 16 F.3d at 382-83, 29 USPQ2d at 1552 (reversing obviousness
rejection of species in view of large size of genus and disclosed
"optimum" species which differed greatly from and were more complex than
the claimed species); Jones, 958 F.2d at 350, 21 USPQ2d at 1943
(reversing obviousness rejection of novel dicamba salt with acyclic
structure over broad prior art genus encompassing claimed salt, where
disclosed examples of genus were dissimilar in structure, lacking an
ether linkage or being cyclic).

   30. Baird, 16 F.3d at 382, 29 USPQ2d at 1552. See also Jones, 958 F.2d
at 350, 21 USPQ2d at 1943 (disclosed salts of genus held not
sufficiently similar in structure to render claimed species prima facie
obvious).

   31. For example, a claimed tetra-orthoester fuel composition was held to
be obvious in light of a prior art tri-orthoester fuel composition based
on their structural and chemical similarity and similar use as fuel
additives. Dillon, 919 F.2d at 692-93, 16 USPQ2d at 1900-02.

   Likewise, claims to amitriptyline used as an antidepressant were held
obvious in light of the structural similarity to imipramine, a known
antidepressant prior art compound, where both compounds were tricyclic
dibenzo compounds and differed structurally only in the replacement of
the unsaturated 24 carbon atom in the center ring of amitriptyline with
a nitrogen atom in imipramine. In re Merck & Co., 800 F.2d 1091,
1096-97, 231 USPQ 375, 378-79 (Fed. Cir. 1986).

   Similarly, a claimed protein compound having an amino acid sequence
including Met-Phe-Pro-Leu-(Asp)4-Lys-Y was held to be obvious in light
of structural similarities to the prior art. One reference provided
motivation to create fusion proteins in the forms X-(Asp)4-Lys-Y. Other
references taught positioning Met at the start of the amino acid
sequence and that the sequences Phe-Pro-Ile or Leu-Pro-Leu could serve
as X in the basic formula. The known structural similarity of Ile and
Leu meant that appellants merely substituted one element known in the
art for a known equivalent. Thus, the substitution was held to be
obvious. In re Mayne, No. 95-1522, slip op. at 6-8 (Fed. Cir. Jan. 17,
1997).

   Other structural similarities have been found to support a prima facie
case of obviousness. E.g., In re May, 574 F.2d 1082, 1093-95, 197 USPQ
601, 610-11 (CCPA 1978) (stereoisomers); In re Wilder, 563 F.2d 457,
460, 195 USPQ 426, 429 (CCPA 1977) (adjacent homologs and structural
isomers); In re Hoch, 428 F.2d 1341, 1344, 166 USPQ 406, 409 (CCPA 1970)
(acid and ethyl ester); In re Druey, 319 F.2d 237, 240, 138 USPQ 39, 41
(CCPA 1963) (omission of methyl group from pyrazole ring).

   32. Id.

   33. Dillon, 919 F.2d at 697, 16 USPQ2d at 1905; In re Stemniski, 444
F.2d 581, 586, 170 USPQ 343, 348 (CCPA 1971).

   34. In re Albrecht, 514 F.2d 1389, 1392, 1395-96, 185 USPQ 585, 587, 590
(CCPA 1975)(The prior art compound so irritated the skin that it could
not be regarded as useful for the disclosed anesthetic purpose, and
therefore a person skilled in the art would not have been motivated to
make related compounds.); Stemniski, 444 F.2d at 586, 170 USPQ at 348
(close structural similarity alone is not sufficient to create a prima
facie case of obviousness when the reference compounds lack utility, and
thus there is no motivation to make related compounds.).

   35. Dillon, 919 F.2d at 697, 16 USPQ2d at 1904-05 (and cases cited
therein).

   36. E.g., id.

   37. Id. at 692, 16 USPQ2d at 1900-01.

   38. Dillon, 919 F.2d at 693, 696, 16 USPQ2d at 1901, 1904. See also In
re Grabiak, 769 F.2d 729, 731, 226 USPQ 870, 871 (Fed. Cir. 1985) ("When
chemical compounds have 'very close' structural similarities and similar
utilities, without more a prima facie case may be made.").

   39. Dillon, 919 F.2d at 697-98, 16 USPQ2d at 1905; In re Wilder, 563
F.2d 457, 461, 195 USPQ 426, 430 (CCPA 1977); In re Linter, 458 F.2d
1013, 1016, 173 USPQ 560, 562 (CCPA 1972).

   40. See, e.g., Dillon, 919 F.2d at 692-97, 16 USPQ2d at 1901-05; In re
Grabiak, 769 F.ld 729, 732-33,226 USPQ 870, 872 (Fed. Cir. 1985).

   41. See e.g., In re May, 574 F.2d 1082, 1094, 197 USPQ 601, 611 (CCPA
1978) (prima facie obviousness of claimed analgesic compound based on
structurally similar prior art isomer was rebutted with evidence
demonstrating that analgesia and addiction properties could not be
reliably predicted on the basis of chemical structure); In re Schechter,
205 F.2d 185,191, 98 USPQ 144, 150 (CCPA 1953) (unpredictability in the
insecticide field, with homologs, isomers and analogs of known effective
insecticides having proven ineffective as insecticides, was considered
as a factor weighing against a conclusion of obviousness of the claimed
compounds).

   42. See, e.g., In re O'Farrell, 853 F.2d 894, 903, 7 USPQ2d 1673, 1681
(Fed. Cir. 1988).

   43. In re Bell, 991 F.2d 781, 784, 26 USPQ2d 1529, 1531 (Fed. Cir.
1993); In re Kulling, 897 F.2d 1147, 1149, 14 USPQ2d 1056, 1057 (Fed.
Cir. 1990).

   44. Kulling, 897 F.2d at 1149, 14 USPQ2d at 1058; Panduit Corp. v.
Dennison Mfg. Co., 810 F.2d 1561, 1579 n.42, 1 USQP2d 1593, 1606 n.42
(Fed. Cir.), cert. denied, 481 U.S. 1052 (1987).

   45. E.g., Dillon, 919 F.2d at 692, 16 USPQ2d at 1901.

   46. In re Soni, 54 F.3d 746, 750, 34 USPQ2d 1684, 1687 (Fed. Cir. 1995).

   47. In re Chu, 66 F.3d 292, 299, 36 USPQ2d 1089, 1094-95 (Fed. Cir.
1995).

   48. E.g., Soni, 54 F.3d at 750, 34 USPQ2d at 1687; In re Piasecki, 745
F.2d 1468, 1474, 223 USPQ 785, 789-90 (Fed. Cir. 1984).

   49. E.g., In re Huang, 100 F.3d 135, 139-40, 40 USPQ2d 1685, 1689 (Fed.
Cir. 1996); In re De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed.
Cir. 1984).

   50. E.g., In re Soni, 54 F.3d 746, 750, 34 USPQ2d 1684, 1687 (Fed. Cir.
1995) (error not to consider evidence presented in the specification).
C.f., In re Alton, 76 F.3d 1168, 37 USPQ2d 1578 (Fed. Cir. 1996) (error
not to consider factual evidence submitted to counter a section 112
rejection); In re Beattie, 974 F.2d 1309, 1313, 24 USPQ2d 1040, 1042-43
(Fed. Cir. 1992) (Office personnel should consider declarations from
those skilled in the art praising the claimed invention and opining that
the art teaches away from the invention.); Piasecki, 745 F.2d at 1472,
223 USPQ at 788 ("[Rebuttal evidence] may relate to any of the Graham
factors including the so-called secondary considerations.").

   51. Graham v. John Deere Co., 383 U.S. at 17, 148 USPQ at 467. See also,
e.g., In re Piasecki, 745 F.2d 1468, 1473, 223 USPQ 785, 788 (Fed. Cir.
1984) (commercial success).

   52. Rebuttal evidence may consist of a showing that the claimed compound
possesses unexpected properties. Dillon, 919 F.2d at 692-93, 16 USPQ2d
at 1901. A showing of unexpected results must be based on evidence, not
argument or speculation. In re Mayne, No. 95-1522, slip op. at 9-10
(Fed. Cir. Jan. 17, 1997) (conclusory statements that claimed compound
posesses unusually low immune response or unexpected biological activity
that is unsupported by comparative data held insufficient to overcome
prima facie case of obviousness).

   53. E.g., In re GPAC, 57 F.3d 1573, 1580, 35 USPQ2d 1116, 1121 (Fed.
Cir. 1995); Hybritech Inc. v. Monoclonal Antibodies, 802 F.2d 1367,
1380, 231 USPQ 81, 90 (Fed. Cir. 1986), cert. denied, 480 U.S. 947
(1987).

   54. E.g., In re Oelrich, 579 F.2d 86, 91-92, 198 USPQ 210, 214 (CCPA
1978) (Expert opinions regarding the level of skill in the art were
probative of the nonobviousness of the claimed invention.); Piasecki,
745 F.2d at 1471, 1473-74, 223 USPQ at 790 (Evidence of
non-technological nature is pertinent to the conclusion of obviousness.
The declarations of those skilled in the art regarding the need for the
invention and its reception by the art were improperly discounted by the
Board); Beattie, 974 F.2d at 1313, 24 USPQ2d at 1042-43 (Seven
declarations provided by music teachers opining that the art teaches
away from the claimed invention must be considered, but were not
probative because they did not contain facts and did not deal with the
specific prior art that was the subject of the rejection.).

   55. Id. See also In re Alton, 76 F.3d 1168, 1174-75, 37 USPQ2d 1578,
1582-83 (Fed. Cir. 1996).

   56. The Federal Circuit has acknowledged that applicant bears the burden
of establishing nexus, stating:

   In the ex parte process of examining a patent application, however, the
PTO lacks the means or resources to gather evidence which supports or
refutes the applicant's assertion that the sales constitute commercial
success. c.f. Ex parte Remark, 15 USPQ2d 1498, 1503 ([BPAI] 1990)
(evidentiary routine of shifting burdens in civil proceedings
inappropriate in ex parte prosecution proceedings because examiner has
no available means for adducing evidence). Consequently, the PTO must
rely upon the applicant to provide hard evidence of commercial success.

   In re Huang, 100 F.3d 135, 139-40, 40 USPQ2d 1685, 1689 (Fed. Cir.
1996). See also GPAC, 57 F.3d at 1580, 35 USPQ2d at 1121; In re Paulsen,
30 F.3d 1475, 1482, 31 USPQ2d 1671,1676 (Fed. Cir. 1994).

   57. E.g., Paulsen, 30 F.3d at 1482, 31 USPQ2d at 1676. (Evidence of
commercial success of articles not covered by the claims subject to the
35 U.S.C.    103 rejection was not probative of nonobviousness).

   58. E.g., In re Kulling, 897 F.2d 1147, 1149, 14 USPQ2d 1056, 1058 /Fed.
Cir. 1990); In re Grasselli, 713 F.2d 731, 743, 218 USPQ 769, 777 (Fed.
Cir. 1983). In re Soni, 54 F.3d 746, 34 USPQ2d 1684 (Fed. Cir. 1995)
does not change this analysis. In Soni, the Court declined to consider
the Office's argument that the evidence of non-obviousness was not
commensurate in scope with the claim because it had not been raised by
the Examiner. 54 F.3d at 751, 34 USPQ2d at 1688.

   When considering whether proffered evidence is commensurate in scope
with the claimed invention, Office personnel should not require the
applicant to show unexpected results over the entire range of properties
possessed by a chemical compound or composition. E.g., In re Chupp, 816
F.2d 643,646, 2 USPQ2d 1437, 1439 (Fed. Cir. 1987). Evidence that the
compound or composition possesses superior and unexpected properties in
one of a spectrum of common properties can be sufficient to rebut a
prima facie case of obviousness. Id.

   For example, a showing of unexpected results for a single member of a
claimed subgenus, or a narrow portion of a claimed range would be
sufficient to rebut a prima facie case of obviousness if a skilled
artisan "could ascertain a trend in the exemplified data that would
allow him to reasonably extend the probative value thereof." In re
Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980) (Evidence of
the unobviousness of a broad range can be proven by a narrower range
when one skilled in the art could ascertain a trend that would allow him
to reasonably extend the probative value thereof.). But see, Grasselli,
713 F.2d at 743, 218 USPQ at 778 (evidence of superior properties for
sodium containing composition insufficient to establish the
non-obviousness of broad claims for a catalyst with "an alkali metal"
where it was well known in the catalyst art that different alkali metals
were not interchangeable and applicant had shown unexpected results only
for sodium containing materials); In re Greenfield, 571 F.2d 1185, 1189,
197 USPQ 227, 230 (CCPA 1978) (evidence of superior properties in one
species insufficient to establish the nonobviousness of a subgenus
containing hundreds of compounds); In re Lindner, 457 F.2d 506, 508, 173
USPQ 356,358 (CCPA 1972) (one test not sufficient where there was no
adequate basis for concluding the other claimed compounds would behave
the same way).

   59. E.g., Chupp, 816 F.2d at 646, 2 USPQ2d at 1439; Clemens, 622 F.2d at
1036, 206 USPQ at 296.

   60. Where the claims are not limited to a particular use, and where the
prior art provides other motivation to select a particular species or
subgenus, a showing of a new use may not be sufficient to confer
patentability. See Dillon, 919 F.2d at 692, 16 USPQ2d at 1900-01.

   61. Piasecki, 745 F.2d at 1473, 223 USPQ at 788.

   62. E.g., Piasecki, 745 F.2d at 1472-73, 223 USPQ at 788; In re Eli
Lilly & Co., 902 F.2d 943, 945, 14 USPQ2d 1741, 1743 (Fed. Cir. 1990).

   63. E.g., Piasecki, 745 F.2d at 1472, 223 USPQ at 788; Eli Lilly, 902
F.2d at 945, 14 USPQ2d at 1743.

   64. Dillon, 919 F.2d at 693, 16 USPQ2d at 1901; In re Mills, 916 F.2d
680, 683, 16 USPQ2d 1430, 1433 (Fed. Cir. 1990).