MPEP § 2164.02 — Working and Prophetic Examples (Annotated Rules)

§2164.02 Working and Prophetic Examples

USPTO MPEP version: BlueIron's Update: 2026-01-17

This page consolidates and annotates all enforceable requirements under MPEP § 2164.02, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Working and Prophetic Examples

This section addresses Working and Prophetic Examples. Primary authority: 35 U.S.C. 112(a) and 35 U.S.C. 112. Contains: 4 requirements, 5 guidance statements, 1 permission, and 12 other statements.

Key Rules

Topic

Patent Application Content

11 rules
StatutoryInformativeAlways
[mpep-2164-02-50136a8f3700db75a3cfff44]
Specification Must Be Fully Disclosed Without Undue Experimentation
Note:
The specification need not include an example if it fully discloses the invention in a manner that allows one skilled in the art to practice it without undue experimentation.

The specification need not contain an example if the invention is otherwise disclosed in such manner that one skilled in the art will be able to practice it without an undue amount of experimentation. In re Borkowski, 422 F.2d 904, 908, 164 USPQ 642, 645 (CCPA 1970). Allergan, Inc. v. Sandoz Inc., 796 F.3d 1293, 1310, 115 USPQ2d 2012, 2023 (Fed. Cir. 2015) (“Only a sufficient description enabling a person of ordinary skill in the art to carry out an invention is needed.”). Lack of a working example, however, is a factor to be considered, especially in a case involving an unpredictable and undeveloped art. But because only an enabling disclosure is required, applicant need not describe all actual embodiments.

Jump to MPEP SourcePatent Application Content
StatutoryInformativeAlways
[mpep-2164-02-fe8d5b776c9ffdcd72746546]
Written Description Requirement
Note:
A patent application must provide a sufficient description to enable a person of ordinary skill in the art to practice the invention without undue experimentation.

The specification need not contain an example if the invention is otherwise disclosed in such manner that one skilled in the art will be able to practice it without an undue amount of experimentation. In re Borkowski, 422 F.2d 904, 908, 164 USPQ 642, 645 (CCPA 1970). Allergan, Inc. v. Sandoz Inc., 796 F.3d 1293, 1310, 115 USPQ2d 2012, 2023 (Fed. Cir. 2015) (“Only a sufficient description enabling a person of ordinary skill in the art to carry out an invention is needed.”). Lack of a working example, however, is a factor to be considered, especially in a case involving an unpredictable and undeveloped art. But because only an enabling disclosure is required, applicant need not describe all actual embodiments.

Jump to MPEP SourcePatent Application Content
StatutoryInformativeAlways
[mpep-2164-02-da4a5a3bc90c9e472cf26499]
Lack of Working Example Considered Especially in Unpredictable Art
Note:
In cases involving unpredictable and undeveloped art, the absence of a working example is a factor to consider, but only an enabling disclosure is required.

The specification need not contain an example if the invention is otherwise disclosed in such manner that one skilled in the art will be able to practice it without an undue amount of experimentation. In re Borkowski, 422 F.2d 904, 908, 164 USPQ 642, 645 (CCPA 1970). Allergan, Inc. v. Sandoz Inc., 796 F.3d 1293, 1310, 115 USPQ2d 2012, 2023 (Fed. Cir. 2015) (“Only a sufficient description enabling a person of ordinary skill in the art to carry out an invention is needed.”). Lack of a working example, however, is a factor to be considered, especially in a case involving an unpredictable and undeveloped art. But because only an enabling disclosure is required, applicant need not describe all actual embodiments.

Jump to MPEP SourcePatent Application Content
StatutoryRequiredAlways
[mpep-2164-02-dc1c7c7b66b5c2a8f4a63bc8]
Invention Must Be Described Adequately
Note:
The specification must describe the invention in sufficient detail to enable a skilled person to implement it without undue experimentation, but not all actual embodiments need be described.

The specification need not contain an example if the invention is otherwise disclosed in such manner that one skilled in the art will be able to practice it without an undue amount of experimentation. In re Borkowski, 422 F.2d 904, 908, 164 USPQ 642, 645 (CCPA 1970). Allergan, Inc. v. Sandoz Inc., 796 F.3d 1293, 1310, 115 USPQ2d 2012, 2023 (Fed. Cir. 2015) (“Only a sufficient description enabling a person of ordinary skill in the art to carry out an invention is needed.”). Lack of a working example, however, is a factor to be considered, especially in a case involving an unpredictable and undeveloped art. But because only an enabling disclosure is required, applicant need not describe all actual embodiments.

Jump to MPEP SourcePatent Application Content
StatutoryRecommendedAlways
[mpep-2164-02-19aea660a5052c1b7ada2d18]
Specification Must Not Rely Solely on Prophetic Examples
Note:
The presence of prophetic examples alone cannot be used to assert that a specification is not enabling; instead, the absence of operative embodiments and undue experimentation should determine whether the specification is adequate.

The courts have further cautioned that the presence of prophetic examples alone should not be the basis for asserting that a specification is not enabling; rather, a lack of operative embodiments and undue experimentation should be determinative. Atlas Powder Co. v. E.I. du Pont De Nemours & Co., 750 F.2d 1569, 1577, 224 USPQ 409, 414 (Fed. Cir. 1984).

Jump to MPEP SourcePatent Application Content
StatutoryInformativeAlways
[mpep-2164-02-831e4f305c171c4d58545d08]
Specification Must Not Solely Rely on Prophetic Examples
Note:
The specification must not rely solely on prophetic examples for enabling the invention; instead, it should include operative embodiments and demonstrate that no undue experimentation is required.

The courts have further cautioned that the presence of prophetic examples alone should not be the basis for asserting that a specification is not enabling; rather, a lack of operative embodiments and undue experimentation should be determinative. Atlas Powder Co. v. E.I. du Pont De Nemours & Co., 750 F.2d 1569, 1577, 224 USPQ 409, 414 (Fed. Cir. 1984).

Jump to MPEP SourcePatent Application Content
StatutoryRecommendedAlways
[mpep-2164-02-3434a1449d841927e54c8ca2]
Single Working Example Not Sole Basis for Claim Rejection
Note:
A single working example cannot be the sole reason to reject claims broader than the enabling disclosure. The specification must also disclose a general quality that gives the invention peculiar fitness for its purpose.

The presence of only one working example should never be the sole reason for rejecting claims as being broader than the enabling disclosure, even though it is a factor to be considered along with all the other factors. In some instances, “it may suffice to give an example (or a few examples) if the specification also discloses ‘some general quality… running through” the class that gives it ‘a peculiar fitness for the particular purpose.” Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 611, 2023 USPQ2d 602 (2023) (citing Incandescent Lamp, 159 U. S. 465, 475, 16 S. Ct. 75, 40 L. Ed. 221 (1895)). However, it should be noted that that “[t]he more one claims, the more one must enable.” Id. at 610. To make a valid rejection, the examiner must evaluate all the facts and evidence and state why one would not expect to be able to extrapolate that one example across the entire scope of the claims.

Jump to MPEP SourcePatent Application Content
StatutoryRequiredAlways
[mpep-2164-02-36047516b66c6233441f5475]
Claims Must Be Supported by Adequate Disclosure
Note:
The rule requires that claims must be supported by a sufficient disclosure to enable one of ordinary skill in the art to practice the invention as claimed.

The presence of only one working example should never be the sole reason for rejecting claims as being broader than the enabling disclosure, even though it is a factor to be considered along with all the other factors. In some instances, “it may suffice to give an example (or a few examples) if the specification also discloses ‘some general quality… running through” the class that gives it ‘a peculiar fitness for the particular purpose.” Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 611, 2023 USPQ2d 602 (2023) (citing Incandescent Lamp, 159 U. S. 465, 475, 16 S. Ct. 75, 40 L. Ed. 221 (1895)). However, it should be noted that that “[t]he more one claims, the more one must enable.” Id. at 610. To make a valid rejection, the examiner must evaluate all the facts and evidence and state why one would not expect to be able to extrapolate that one example across the entire scope of the claims.

Jump to MPEP SourcePatent Application Content
StatutoryInformativeAlways
[mpep-2164-02-998e34b7f8fae6eb6779ffe9]
Single Example Insufficient for Broader Claims
Note:
A single working example cannot solely reject broader claims unless the specification lacks enabling disclosure for that scope.

The presence of only one working example should never be the sole reason for rejecting claims as being broader than the enabling disclosure, even though it is a factor to be considered along with all the other factors. In some instances, “it may suffice to give an example (or a few examples) if the specification also discloses ‘some general quality… running through” the class that gives it ‘a peculiar fitness for the particular purpose.” Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 611, 2023 USPQ2d 602 (2023) (citing Incandescent Lamp, 159 U. S. 465, 475, 16 S. Ct. 75, 40 L. Ed. 221 (1895)). However, it should be noted that that “[t]he more one claims, the more one must enable.” Id. at 610. To make a valid rejection, the examiner must evaluate all the facts and evidence and state why one would not expect to be able to extrapolate that one example across the entire scope of the claims.

Jump to MPEP SourcePatent Application Content
StatutoryRequiredAlways
[mpep-2164-02-9c67f96735cdc38c86479164]
Examiner Must Evaluate All Evidence for Extrapolation
Note:
The examiner must evaluate all facts and evidence to determine why one example cannot be extrapolated across the entire claims scope.

The presence of only one working example should never be the sole reason for rejecting claims as being broader than the enabling disclosure, even though it is a factor to be considered along with all the other factors. In some instances, “it may suffice to give an example (or a few examples) if the specification also discloses ‘some general quality… running through” the class that gives it ‘a peculiar fitness for the particular purpose.” Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 611, 2023 USPQ2d 602 (2023) (citing Incandescent Lamp, 159 U. S. 465, 475, 16 S. Ct. 75, 40 L. Ed. 221 (1895)). However, it should be noted that that “[t]he more one claims, the more one must enable.” Id. at 610. To make a valid rejection, the examiner must evaluate all the facts and evidence and state why one would not expect to be able to extrapolate that one example across the entire scope of the claims.

Jump to MPEP SourcePatent Application Content
StatutoryInformativeAlways
[mpep-2164-02-f15209722d49b68c7d0356a3]
Prophetic Examples Must Not Be Represented as Actual Results
Note:
Patent applicants must not represent prophetic examples as actual results unless they have been achieved, ensuring the adequacy and accuracy of disclosure.

When prophetic examples are described in a manner that is ambiguous or that implies that the results are actual, the adequacy and accuracy of the disclosure may come into question. If the characterization of the results, when taken in light of the disclosure as a whole, reasonably raises any questions as to whether the results from the examples are actual, the examiner should determine whether to reject the appropriate claims based on an insufficient disclosure under the enablement and/or written description requirements of 35 U.S.C. 112(a) following the guidance in MPEP §§ 2164 and 2163, respectively. When such a rejection(s) is made, the applicant should reply with the results of an actual test or example that has been conducted, or by providing relevant arguments and/or declaration evidence that there is strong reason to believe that the result would be as predicted, being careful not to introduce new matter into the application. See Hoffmann-La Roche, Inc. v. Promega Corp., 323 F.3d. 1354, 1367, 66 USPQ2d 1385, 1394 (Fed. Cir. 2003) (improperly identifying a prophetic example in the past tense validly raises an inequitable conduct issue based on the intent of the inventors in drafting the example in the past tense, when the example, in fact, is prophetic); and Apotex Inc. v. UCB, Inc., 763 F.3d 1354, 1362, 112 USPQ2d 1081, 1087 (Fed. Cir. 2014) (the inventor “admitted that he never performed the experiments described in the… patent, and yet he drafted the examples in the specification entirely in past-tense language.”). No results should be represented as actual results unless they have actually been achieved. See MPEP § 2004, item 8.

Jump to MPEP SourcePatent Application ContentInventor's Oath/Declaration RequirementsSpecification
Topic

Method/Process Claims

6 rules
StatutoryInformativeAlways
[mpep-2164-02-9fa1e600bc76b0914fbcf633]
Correlation Between Assays and Methods Required
Note:
The presence of working examples is dependent on the correlation between in vitro or in vivo assays and claimed methods, which must be established based on the state of the prior art.

The issue of “correlation” is related to the issue of the presence or absence of working examples. “Correlation” as used herein refers to the relationship between in vitro or in vivo animal model assays and a disclosed or a claimed method of use. An in vitro or in vivo animal model example in the specification, in effect, constitutes a “working example” if that example “correlates” with a disclosed or claimed method invention. If there is no correlation, then the examples do not constitute “working examples.” In this regard, the issue of “correlation” is also dependent on the state of the prior art. In other words, if the art is such that a particular model is recognized as correlating to a specific condition, then it should be accepted as correlating unless the examiner has evidence that the model does not correlate. Even with such evidence, the examiner must weigh the evidence for and against correlation and decide whether one skilled in the art would accept the model as reasonably correlating to the condition. In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) (reversing a USPTO decision based on finding that in vitro data did not support in vivo applications).

Jump to MPEP SourceMethod/Process ClaimsPatent Application Content
StatutoryInformativeAlways
[mpep-2164-02-996cd2131cd76176cb91d507]
Correlation Between Assays and Method Claims Must Be Established
Note:
The rule requires that in vitro or in vivo animal model assays must correlate with the disclosed or claimed method of use for them to be considered working examples.

The issue of “correlation” is related to the issue of the presence or absence of working examples. “Correlation” as used herein refers to the relationship between in vitro or in vivo animal model assays and a disclosed or a claimed method of use. An in vitro or in vivo animal model example in the specification, in effect, constitutes a “working example” if that example “correlates” with a disclosed or claimed method invention. If there is no correlation, then the examples do not constitute “working examples.” In this regard, the issue of “correlation” is also dependent on the state of the prior art. In other words, if the art is such that a particular model is recognized as correlating to a specific condition, then it should be accepted as correlating unless the examiner has evidence that the model does not correlate. Even with such evidence, the examiner must weigh the evidence for and against correlation and decide whether one skilled in the art would accept the model as reasonably correlating to the condition. In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) (reversing a USPTO decision based on finding that in vitro data did not support in vivo applications).

Jump to MPEP SourceMethod/Process ClaimsPatent Application Content
StatutoryInformativeAlways
[mpep-2164-02-e24da15955e424c8da64bc66]
Working Examples Require Correlation
Note:
Examples must correlate with the disclosed method for them to be considered working examples.

The issue of “correlation” is related to the issue of the presence or absence of working examples. “Correlation” as used herein refers to the relationship between in vitro or in vivo animal model assays and a disclosed or a claimed method of use. An in vitro or in vivo animal model example in the specification, in effect, constitutes a “working example” if that example “correlates” with a disclosed or claimed method invention. If there is no correlation, then the examples do not constitute “working examples.” In this regard, the issue of “correlation” is also dependent on the state of the prior art. In other words, if the art is such that a particular model is recognized as correlating to a specific condition, then it should be accepted as correlating unless the examiner has evidence that the model does not correlate. Even with such evidence, the examiner must weigh the evidence for and against correlation and decide whether one skilled in the art would accept the model as reasonably correlating to the condition. In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) (reversing a USPTO decision based on finding that in vitro data did not support in vivo applications).

Jump to MPEP SourceMethod/Process ClaimsPatent Application Content
StatutoryInformativeAlways
[mpep-2164-02-3905f6fc4b893a4c5a521522]
Correlation of Examples to State of the Art Required
Note:
The examples in the specification must correlate with the claimed method invention based on the state of the prior art. The examiner must weigh evidence for and against correlation, deciding if a skilled artisan would accept the model as reasonably correlating to the condition.

The issue of “correlation” is related to the issue of the presence or absence of working examples. “Correlation” as used herein refers to the relationship between in vitro or in vivo animal model assays and a disclosed or a claimed method of use. An in vitro or in vivo animal model example in the specification, in effect, constitutes a “working example” if that example “correlates” with a disclosed or claimed method invention. If there is no correlation, then the examples do not constitute “working examples.” In this regard, the issue of “correlation” is also dependent on the state of the prior art. In other words, if the art is such that a particular model is recognized as correlating to a specific condition, then it should be accepted as correlating unless the examiner has evidence that the model does not correlate. Even with such evidence, the examiner must weigh the evidence for and against correlation and decide whether one skilled in the art would accept the model as reasonably correlating to the condition. In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) (reversing a USPTO decision based on finding that in vitro data did not support in vivo applications).

Jump to MPEP SourceMethod/Process ClaimsPatent Application Content
StatutoryRecommendedAlways
[mpep-2164-02-92f46b58f5a2626198459297]
Model Correlation Must Be Established
Note:
If a model is recognized as correlating to a specific condition, it must be accepted unless the examiner provides evidence that it does not correlate.

The issue of “correlation” is related to the issue of the presence or absence of working examples. “Correlation” as used herein refers to the relationship between in vitro or in vivo animal model assays and a disclosed or a claimed method of use. An in vitro or in vivo animal model example in the specification, in effect, constitutes a “working example” if that example “correlates” with a disclosed or claimed method invention. If there is no correlation, then the examples do not constitute “working examples.” In this regard, the issue of “correlation” is also dependent on the state of the prior art. In other words, if the art is such that a particular model is recognized as correlating to a specific condition, then it should be accepted as correlating unless the examiner has evidence that the model does not correlate. Even with such evidence, the examiner must weigh the evidence for and against correlation and decide whether one skilled in the art would accept the model as reasonably correlating to the condition. In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) (reversing a USPTO decision based on finding that in vitro data did not support in vivo applications).

Jump to MPEP SourceMethod/Process ClaimsPatent Application Content
StatutoryRequiredAlways
[mpep-2164-02-07fc4dd6830942bf66d4fe85]
Examiner Must Weigh Correlation Evidence
Note:
The examiner must evaluate evidence for and against the correlation between in vitro or in vivo data and a claimed method, deciding if it reasonably correlates to the condition.

The issue of “correlation” is related to the issue of the presence or absence of working examples. “Correlation” as used herein refers to the relationship between in vitro or in vivo animal model assays and a disclosed or a claimed method of use. An in vitro or in vivo animal model example in the specification, in effect, constitutes a “working example” if that example “correlates” with a disclosed or claimed method invention. If there is no correlation, then the examples do not constitute “working examples.” In this regard, the issue of “correlation” is also dependent on the state of the prior art. In other words, if the art is such that a particular model is recognized as correlating to a specific condition, then it should be accepted as correlating unless the examiner has evidence that the model does not correlate. Even with such evidence, the examiner must weigh the evidence for and against correlation and decide whether one skilled in the art would accept the model as reasonably correlating to the condition. In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) (reversing a USPTO decision based on finding that in vitro data did not support in vivo applications).

Jump to MPEP SourceMethod/Process ClaimsPatent Application Content
Topic

Working and Prophetic Examples (MPEP 2164.02)

5 rules
StatutoryInformativeAlways
[mpep-2164-02-f8dfae5ea9c5f94b4a564a50]
Enablement Not Dependent on Example Disclosure
Note:
The enablement requirement for section 112(a) is not determined by whether an example is disclosed, whether it be a working or prophetic example.

Compliance with the enablement requirement of 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, does not turn on whether an example is disclosed. An example may be “working” or “prophetic.” A working example is based on work actually performed. A prophetic example describes an embodiment of the invention based on predicted results rather than work actually conducted or results actually achieved. The claims should be drafted in a manner that assists readers in differentiating between actual working examples and prophetic examples (i.e., prophetic examples should not be described using the past tense, but rather in future or present tense).

Jump to MPEP SourceWorking and Prophetic Examples (MPEP 2164.02)35 U.S.C. 112(a) – Written Description & EnablementDisclosure Requirements
StatutoryPermittedAlways
[mpep-2164-02-38f8a352a84b47131bf97b7b]
Prophetic Examples Must Be Described in Future Tense
Note:
The claims should be drafted to differentiate between actual working examples and predicted results, with prophetic examples described using future or present tense.

Compliance with the enablement requirement of 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, does not turn on whether an example is disclosed. An example may be “working” or “prophetic.” A working example is based on work actually performed. A prophetic example describes an embodiment of the invention based on predicted results rather than work actually conducted or results actually achieved. The claims should be drafted in a manner that assists readers in differentiating between actual working examples and prophetic examples (i.e., prophetic examples should not be described using the past tense, but rather in future or present tense).

Jump to MPEP SourceWorking and Prophetic Examples (MPEP 2164.02)35 U.S.C. 112(a) – Written Description & EnablementDisclosure Requirements
StatutoryInformativeAlways
[mpep-2164-02-9d466ca3cf2b03ac30f4c8f7]
Working Example Based on Actual Performance
Note:
A working example must be based on actual work performed, distinguishing it from a prophetic example which describes predicted results.

Compliance with the enablement requirement of 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, does not turn on whether an example is disclosed. An example may be “working” or “prophetic.” A working example is based on work actually performed. A prophetic example describes an embodiment of the invention based on predicted results rather than work actually conducted or results actually achieved. The claims should be drafted in a manner that assists readers in differentiating between actual working examples and prophetic examples (i.e., prophetic examples should not be described using the past tense, but rather in future or present tense).

Jump to MPEP SourceWorking and Prophetic Examples (MPEP 2164.02)35 U.S.C. 112(a) – Written Description & EnablementDisclosure Requirements
StatutoryInformativeAlways
[mpep-2164-02-cea01776af4f4c449abe7e19]
Prophetic Example Description Not Past Tense
Note:
A prophetic example should describe predicted results without using past tense, ensuring clarity about unverified claims.

Compliance with the enablement requirement of 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, does not turn on whether an example is disclosed. An example may be “working” or “prophetic.” A working example is based on work actually performed. A prophetic example describes an embodiment of the invention based on predicted results rather than work actually conducted or results actually achieved. The claims should be drafted in a manner that assists readers in differentiating between actual working examples and prophetic examples (i.e., prophetic examples should not be described using the past tense, but rather in future or present tense).

Jump to MPEP SourceWorking and Prophetic Examples (MPEP 2164.02)35 U.S.C. 112(a) – Written Description & EnablementDisclosure Requirements
StatutoryRecommendedAlways
[mpep-2164-02-af41f747dae5bbdc9c183368]
Prophetic Examples Must Use Future/Present Tense
Note:
Claims should distinguish between actual working examples and prophetic examples by using future or present tense for the latter.

Compliance with the enablement requirement of 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, does not turn on whether an example is disclosed. An example may be “working” or “prophetic.” A working example is based on work actually performed. A prophetic example describes an embodiment of the invention based on predicted results rather than work actually conducted or results actually achieved. The claims should be drafted in a manner that assists readers in differentiating between actual working examples and prophetic examples (i.e., prophetic examples should not be described using the past tense, but rather in future or present tense).

Jump to MPEP SourceWorking and Prophetic Examples (MPEP 2164.02)35 U.S.C. 112(a) – Written Description & EnablementDisclosure Requirements
Topic

Undue Experimentation

3 rules
StatutoryInformativeAlways
[mpep-2164-02-a0aa3b7169d5ac316f51b111]
Genus Enablement With Representative Examples
Note:
A claimed genus can be enabled with representative examples and a general statement if a skilled artisan would expect it to work without undue experimentation.

For a claimed genus, representative examples together with a statement applicable to the genus as a whole will ordinarily be sufficient if one skilled in the art (in view of level of skill, state of the art and the information in the specification) would expect the claimed genus could be used in that manner without undue experimentation. Proof of enablement will be required for other members of the claimed genus only where adequate reasons are advanced by the examiner to establish that a person skilled in the art could not use the genus as a whole without undue experimentation. In some instances “it may suffice to give an example (or a few examples) if the specification also discloses ‘some general quality… running through’ the class that gives it ‘a peculiar fitness for the particular purpose.’” Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 611, 2023 USPQ2d 602 (2023) (citing Incandescent Lamp, 159 U. S., at 475, 16 S. Ct. 75, 40 L. Ed. 221, 1895 Dec. Comm'r Pat. 675).

Jump to MPEP SourceUndue ExperimentationTest of Enablement (MPEP 2164.01)Level of Ordinary Skill (Wands Factor)
StatutoryRequiredAlways
[mpep-2164-02-041e24420dea5a168e6e50db]
Enablement for Genus Requires Examples Only When Undue Experimentation Is Likely
Note:
If a skilled artisan could use the genus without undue experimentation, examples may suffice; otherwise, proof of enablement is required.

For a claimed genus, representative examples together with a statement applicable to the genus as a whole will ordinarily be sufficient if one skilled in the art (in view of level of skill, state of the art and the information in the specification) would expect the claimed genus could be used in that manner without undue experimentation. Proof of enablement will be required for other members of the claimed genus only where adequate reasons are advanced by the examiner to establish that a person skilled in the art could not use the genus as a whole without undue experimentation. In some instances “it may suffice to give an example (or a few examples) if the specification also discloses ‘some general quality… running through’ the class that gives it ‘a peculiar fitness for the particular purpose.’” Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 611, 2023 USPQ2d 602 (2023) (citing Incandescent Lamp, 159 U. S., at 475, 16 S. Ct. 75, 40 L. Ed. 221, 1895 Dec. Comm'r Pat. 675).

Jump to MPEP SourceUndue ExperimentationTest of Enablement (MPEP 2164.01)Enablement Support for Claims
StatutoryInformativeAlways
[mpep-2164-02-dab938d64c88da638f2a602a]
Representative Examples and General Quality for Genus Enablement
Note:
A claimed genus requires representative examples and a general quality that makes it enableable without undue experimentation.

For a claimed genus, representative examples together with a statement applicable to the genus as a whole will ordinarily be sufficient if one skilled in the art (in view of level of skill, state of the art and the information in the specification) would expect the claimed genus could be used in that manner without undue experimentation. Proof of enablement will be required for other members of the claimed genus only where adequate reasons are advanced by the examiner to establish that a person skilled in the art could not use the genus as a whole without undue experimentation. In some instances “it may suffice to give an example (or a few examples) if the specification also discloses ‘some general quality… running through’ the class that gives it ‘a peculiar fitness for the particular purpose.’” Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 611, 2023 USPQ2d 602 (2023) (citing Incandescent Lamp, 159 U. S., at 475, 16 S. Ct. 75, 40 L. Ed. 221, 1895 Dec. Comm'r Pat. 675).

Jump to MPEP SourceUndue ExperimentationTest of Enablement (MPEP 2164.01)Level of Ordinary Skill (Wands Factor)
Topic

Inventor's Oath/Declaration Requirements

3 rules
StatutoryPermittedAlways
[mpep-2164-02-57b4285c617ead91b986e194]
Disclosure of Prophetic Examples Must Be Clear and Accurate
Note:
The disclosure must clearly indicate that prophetic examples are not actual results, avoiding ambiguity and ensuring the adequacy of the written description.

When prophetic examples are described in a manner that is ambiguous or that implies that the results are actual, the adequacy and accuracy of the disclosure may come into question. If the characterization of the results, when taken in light of the disclosure as a whole, reasonably raises any questions as to whether the results from the examples are actual, the examiner should determine whether to reject the appropriate claims based on an insufficient disclosure under the enablement and/or written description requirements of 35 U.S.C. 112(a) following the guidance in MPEP §§ 2164 and 2163, respectively. When such a rejection(s) is made, the applicant should reply with the results of an actual test or example that has been conducted, or by providing relevant arguments and/or declaration evidence that there is strong reason to believe that the result would be as predicted, being careful not to introduce new matter into the application. See Hoffmann-La Roche, Inc. v. Promega Corp., 323 F.3d. 1354, 1367, 66 USPQ2d 1385, 1394 (Fed. Cir. 2003) (improperly identifying a prophetic example in the past tense validly raises an inequitable conduct issue based on the intent of the inventors in drafting the example in the past tense, when the example, in fact, is prophetic); and Apotex Inc. v. UCB, Inc., 763 F.3d 1354, 1362, 112 USPQ2d 1081, 1087 (Fed. Cir. 2014) (the inventor “admitted that he never performed the experiments described in the… patent, and yet he drafted the examples in the specification entirely in past-tense language.”). No results should be represented as actual results unless they have actually been achieved. See MPEP § 2004, item 8.

Jump to MPEP SourceInventor's Oath/Declaration RequirementsSpecificationPatent Application Content
StatutoryRecommendedAlways
[mpep-2164-02-e3675eb5a8dd0bfe42a1e21c]
Requirement for Actual Test Results After Rejection
Note:
Applicants must provide actual test results or strong evidence supporting predicted outcomes after receiving a rejection, without introducing new matter.

When prophetic examples are described in a manner that is ambiguous or that implies that the results are actual, the adequacy and accuracy of the disclosure may come into question. If the characterization of the results, when taken in light of the disclosure as a whole, reasonably raises any questions as to whether the results from the examples are actual, the examiner should determine whether to reject the appropriate claims based on an insufficient disclosure under the enablement and/or written description requirements of 35 U.S.C. 112(a) following the guidance in MPEP §§ 2164 and 2163, respectively. When such a rejection(s) is made, the applicant should reply with the results of an actual test or example that has been conducted, or by providing relevant arguments and/or declaration evidence that there is strong reason to believe that the result would be as predicted, being careful not to introduce new matter into the application. See Hoffmann-La Roche, Inc. v. Promega Corp., 323 F.3d. 1354, 1367, 66 USPQ2d 1385, 1394 (Fed. Cir. 2003) (improperly identifying a prophetic example in the past tense validly raises an inequitable conduct issue based on the intent of the inventors in drafting the example in the past tense, when the example, in fact, is prophetic); and Apotex Inc. v. UCB, Inc., 763 F.3d 1354, 1362, 112 USPQ2d 1081, 1087 (Fed. Cir. 2014) (the inventor “admitted that he never performed the experiments described in the… patent, and yet he drafted the examples in the specification entirely in past-tense language.”). No results should be represented as actual results unless they have actually been achieved. See MPEP § 2004, item 8.

Jump to MPEP SourceInventor's Oath/Declaration RequirementsSpecificationPatent Application Content
StatutoryRecommendedAlways
[mpep-2164-02-9b8852a66aeb041942898d2e]
Prophetic Examples Must Be Supported by Actual Results
Note:
Inventors must not represent prophetic examples as actual results unless they have been achieved, ensuring disclosure accuracy.

When prophetic examples are described in a manner that is ambiguous or that implies that the results are actual, the adequacy and accuracy of the disclosure may come into question. If the characterization of the results, when taken in light of the disclosure as a whole, reasonably raises any questions as to whether the results from the examples are actual, the examiner should determine whether to reject the appropriate claims based on an insufficient disclosure under the enablement and/or written description requirements of 35 U.S.C. 112(a) following the guidance in MPEP §§ 2164 and 2163, respectively. When such a rejection(s) is made, the applicant should reply with the results of an actual test or example that has been conducted, or by providing relevant arguments and/or declaration evidence that there is strong reason to believe that the result would be as predicted, being careful not to introduce new matter into the application. See Hoffmann-La Roche, Inc. v. Promega Corp., 323 F.3d. 1354, 1367, 66 USPQ2d 1385, 1394 (Fed. Cir. 2003) (improperly identifying a prophetic example in the past tense validly raises an inequitable conduct issue based on the intent of the inventors in drafting the example in the past tense, when the example, in fact, is prophetic); and Apotex Inc. v. UCB, Inc., 763 F.3d 1354, 1362, 112 USPQ2d 1081, 1087 (Fed. Cir. 2014) (the inventor “admitted that he never performed the experiments described in the… patent, and yet he drafted the examples in the specification entirely in past-tense language.”). No results should be represented as actual results unless they have actually been achieved. See MPEP § 2004, item 8.

Jump to MPEP SourceInventor's Oath/Declaration RequirementsSpecificationPatent Application Content
Topic

Scope Commensurate with Disclosure

2 rules
StatutoryInformativeAlways
[mpep-2164-02-040063db7f1e21b919410487]
Absence of Examples Does Not Render Invention Non-Enabled
Note:
If other factors support enablement, the lack of working examples should not alone reject the invention as non-enabled.

When considering the factors relating to a determination of non-enablement, if all the other factors point toward enablement, then the absence of working examples will not by itself render the invention non-enabled. In other words, lack of working examples or lack of evidence that the claimed invention works as described should never be the sole reason for rejecting the claimed invention on the grounds of lack of enablement. A single working example in the specification for a claimed invention is enough to preclude a rejection which states that nothing is enabled since at least that embodiment would be enabled. However, a rejection stating that enablement is limited to a particular scope may be appropriate.

Jump to MPEP SourceScope Commensurate with DisclosureEnablement Support for Claims
StatutoryPermittedAlways
[mpep-2164-02-651c944cece6f61c12ce9000]
Single Working Example Sufficient for Enablement
Note:
A single working example in the specification is enough to establish enablement, even if other examples are missing. However, a rejection limiting enablement scope may be appropriate.

When considering the factors relating to a determination of non-enablement, if all the other factors point toward enablement, then the absence of working examples will not by itself render the invention non-enabled. In other words, lack of working examples or lack of evidence that the claimed invention works as described should never be the sole reason for rejecting the claimed invention on the grounds of lack of enablement. A single working example in the specification for a claimed invention is enough to preclude a rejection which states that nothing is enabled since at least that embodiment would be enabled. However, a rejection stating that enablement is limited to a particular scope may be appropriate.

Jump to MPEP SourceScope Commensurate with DisclosureEnablement Support for Claims
Topic

Enablement Support for Claims

1 rules
StatutoryRecommendedAlways
[mpep-2164-02-2a10600493dffcdbe385d9b9]
Working Examples Not Sole Basis for Enablement Rejection
Note:
Lack of working examples cannot be the sole reason to reject a claimed invention on enablement grounds. At least one example is sufficient to establish enablement.

When considering the factors relating to a determination of non-enablement, if all the other factors point toward enablement, then the absence of working examples will not by itself render the invention non-enabled. In other words, lack of working examples or lack of evidence that the claimed invention works as described should never be the sole reason for rejecting the claimed invention on the grounds of lack of enablement. A single working example in the specification for a claimed invention is enough to preclude a rejection which states that nothing is enabled since at least that embodiment would be enabled. However, a rejection stating that enablement is limited to a particular scope may be appropriate.

Jump to MPEP SourceEnablement Support for ClaimsScope Commensurate with Disclosure
Topic

Claims

1 rules
StatutoryInformativeAlways
[mpep-2164-02-6b4444d8918b35f0fbc95b96]
Working Example Must Correlate with Method Invention
Note:
A working example in the specification must demonstrate a correlation between an in vitro or in vivo animal model and the disclosed or claimed method of use.

The issue of “correlation” is related to the issue of the presence or absence of working examples. “Correlation” as used herein refers to the relationship between in vitro or in vivo animal model assays and a disclosed or a claimed method of use. An in vitro or in vivo animal model example in the specification, in effect, constitutes a “working example” if that example “correlates” with a disclosed or claimed method invention. If there is no correlation, then the examples do not constitute “working examples.” In this regard, the issue of “correlation” is also dependent on the state of the prior art. In other words, if the art is such that a particular model is recognized as correlating to a specific condition, then it should be accepted as correlating unless the examiner has evidence that the model does not correlate. Even with such evidence, the examiner must weigh the evidence for and against correlation and decide whether one skilled in the art would accept the model as reasonably correlating to the condition. In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) (reversing a USPTO decision based on finding that in vitro data did not support in vivo applications).

Jump to MPEP SourcePatent Application ContentMethod/Process Claims
Topic

Specification

1 rules
StatutoryRecommendedAlways
[mpep-2164-02-e1e9a62fb7c210edf06f0dc9]
Requirement for Clear Example Results
Note:
Examiner must determine if claims should be rejected based on insufficient disclosure of example results, requiring actual test evidence or strong arguments.

When prophetic examples are described in a manner that is ambiguous or that implies that the results are actual, the adequacy and accuracy of the disclosure may come into question. If the characterization of the results, when taken in light of the disclosure as a whole, reasonably raises any questions as to whether the results from the examples are actual, the examiner should determine whether to reject the appropriate claims based on an insufficient disclosure under the enablement and/or written description requirements of 35 U.S.C. 112(a) following the guidance in MPEP §§ 2164 and 2163, respectively. When such a rejection(s) is made, the applicant should reply with the results of an actual test or example that has been conducted, or by providing relevant arguments and/or declaration evidence that there is strong reason to believe that the result would be as predicted, being careful not to introduce new matter into the application. See Hoffmann-La Roche, Inc. v. Promega Corp., 323 F.3d. 1354, 1367, 66 USPQ2d 1385, 1394 (Fed. Cir. 2003) (improperly identifying a prophetic example in the past tense validly raises an inequitable conduct issue based on the intent of the inventors in drafting the example in the past tense, when the example, in fact, is prophetic); and Apotex Inc. v. UCB, Inc., 763 F.3d 1354, 1362, 112 USPQ2d 1081, 1087 (Fed. Cir. 2014) (the inventor “admitted that he never performed the experiments described in the… patent, and yet he drafted the examples in the specification entirely in past-tense language.”). No results should be represented as actual results unless they have actually been achieved. See MPEP § 2004, item 8.

Jump to MPEP SourceSpecificationDisclosure RequirementsInventor's Oath/Declaration Requirements

Citations

Primary topicCitation
Working and Prophetic Examples (MPEP 2164.02)35 U.S.C. § 112
Inventor's Oath/Declaration Requirements
Patent Application Content
Specification
Working and Prophetic Examples (MPEP 2164.02)
35 U.S.C. § 112(a)
Inventor's Oath/Declaration Requirements
Patent Application Content
Specification
MPEP § 2004
Inventor's Oath/Declaration Requirements
Patent Application Content
Specification
MPEP § 2164
Patent Application ContentAllergan, Inc. v. Sandoz Inc., 796 F.3d 1293, 1310, 115 USPQ2d 2012, 2023 (Fed. Cir. 2015)
Patent Application Content
Undue Experimentation
Amgen Inc. et al. v. Sanofi et al., 598 U.S. 594, 611, 2023 USPQ2d 602 (2023)
Patent Application ContentIn re Borkowski, 422 F.2d 904, 908, 164 USPQ 642, 645 (CCPA 1970)
Claims
Method/Process Claims
In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995)
In re Chilowsky, 229 F.2d 457, 461, 108 USPQ 321, 325 (CCPA 1956)
Inventor's Oath/Declaration Requirements
Patent Application Content
Specification
and Apotex Inc. v. UCB, Inc., 763 F.3d 1354, 1362, 112 USPQ2d 1081, 1087 (Fed. Cir. 2014)
as stated in Cross v. Iizuka, 753 F.2d 1040, 1050, 224 USPQ 739, 747 (Fed. Cir. 1985)

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2026-01-17