Editing MPEP 2164

<noinclude>{{MPEP Section|2163|2100|2165}}</noinclude>

==[[MPEP 2164|2164 The Enablement Requirement]]==

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The '''enablement requirement''' refers to the requirement 
of 35 U.S.C. 112, first paragraph that the specification 
describe how to make and how to use the 
invention. The invention that one skilled in the art 
must be enabled to make and use is that defined by the 
claim(s) of the particular application or patent.

The purpose of the requirement that the specification 
describe the invention in such terms that 
one skilled in the art can make and use the claimed 
invention is to ensure that the invention is communicated 
to the interested public in a meaningful way. 
The information contained in the disclosure of an 
application must be sufficient to inform those skilled 
in the relevant art how to both make and use the 
claimed invention. However, to comply with 35 
U.S.C. 112, first paragraph, it is not necessary to 
"enable one of ordinary skill in the art to make and 
use a perfected, commercially viable embodiment 
absent a claim limitation to that effect."

Detailed procedures for making and using the invention 
may not be necessary if the description of the 
invention itself is sufficient to permit those skilled in 
the art to make and use the invention. A patent claim 
is invalid if it is not supported by an enabling disclosure.

The enablement requirement of 35 U.S.C. 112, first 
paragraph, is separate and distinct from the description 
requirement. Therefore, the fact that an additional limitation to a claim may 
lack descriptive support in the disclosure as originally 
filed does not necessarily mean that the limitation is 
also not enabled. In other words, the statement of a 
new limitation in and of itself may enable one skilled 
in the art to make and use the claim containing that 
limitation even though that limitation may not be 
described in the original disclosure. Consequently, 
such limitations must be analyzed for both enablement 
and description using their separate and distinct 
criteria.

Furthermore, when the subject matter is not in the 
specification portion of the application as filed but is 
in the claims, the limitation in and of itself may enable 
one skilled in the art to make and use the claim containing 
the limitation. When claimed subject matter is 
only presented in the claims and not in the specification 
portion of the application, the specification 
should be objected to for lacking the requisite support 
for the claimed subject matter. This is an objection to the 
specification only and enablement issues should be 
treated separately.

===2164.01 Test of Enablement===

Any analysis of whether a particular claim is supported 
by the disclosure in an application requires a 
determination of whether that disclosure, when filed, 
contained sufficient information regarding the subject 
matter of the claims as to enable one skilled in the 
pertinent art to make and use the claimed 
invention.

* The standard for determining whether the specification meets the enablement requirement:
** is the experimentation needed to practice the invention undue or unreasonable?
* A patent need not teach, and preferably omits, what is well known in the art.
* Any part of the specification can support an enabling disclosure, even a background section that discusses, or even disparages, the subject matter disclosed therein.

'''UNDUE EXPERIMENTATION'''

* The fact that experimentation may be complex does not necessarily make it undue, if the art typically engages in such experimentation.
* The test of enablement is not whether any experimentation is necessary, but whether, if experimentation is necessary, it is undue.

====2164.01(a) Undue Experimentation Factors====

Factors to be considered when 
determining whether there is sufficient evidence to 
support a determination that a disclosure does not satisfy 
the enablement requirement and whether any necessary 
experimentation is "undue." These factors 
include, but are not limited to: 
* The breadth of the claims; 
* The nature of the invention;
* The state of the prior art;
* The level of one of ordinary skill;
* The level of predictability in the art;
* The amount of direction provided by the inventor;
* The existence of working examples; and 
* The quantity of experimentation needed to make or use the invention based on the content of the disclosure. 

It is improper to conclude that a disclosure is not 
enabling based on an analysis of only one of the 
above factors while ignoring one or more of the others. 
The examiner’s analysis must consider all the evidence 
related to each of these factors, and any 
conclusion of nonenablement must be based on the 
evidence as a whole.

A conclusion of lack of enablement means that, 
based on the evidence regarding each of the above 
factors, the specification, at the time the application 
was filed, would not have taught one skilled in the art 
how to make and/or use the full scope of the claimed 
invention without undue experimentation.

The determination that "undue experimentation" 
would have been needed to make and use the claimed 
invention is not a single, simple factual determination. 
Rather, it is a conclusion reached by weighing all the 
above noted factual considerations.

====2164.01(b) How to Make the Claimed Invention====

As long as the specification discloses at least one 
method for making and using the claimed invention 
that bears a reasonable correlation to the entire scope 
of the claim, then the enablement requirement of 
35 U.S.C. 112 is satisfied.

Failure to disclose other methods by which the claimed invention 
may be made does not render a claim invalid under 
35 U.S.C. 112.

Naturally, for unstable and transitory chemical 
intermediates, the "how to make' requirement does 
not require that the applicant teach how to make the 
claimed product in stable, permanent or isolatable 
form.

A key issue that can arise when determining 
whether the specification is enabling is whether the 
starting materials or apparatus necessary to make the 
invention are available. In the biotechnical area, this 
is often true when the product or process requires a 
particular strain of microorganism and when the 
microorganism is available only after extensive 
screening.

If the 
practice of a method requires a particular apparatus, 
the application must provide a sufficient disclosure of 
the apparatus if the apparatus is not readily available. 
The same can be said if certain chemicals are required 
to make a compound or practice a chemical process. 

====2164.01(c) How to Use the Claimed Invention====

If a statement of utility in the specification contains 
within it a connotation of how to use, and/or the art 
recognizes that standard modes of administration are 
known and contemplated, 35 U.S.C. 112 is satisfied. 

For example, it is not necessary to specify the dosage 
or method of use if it is known to one skilled in 
the art that such information could be obtained without 
undue experimentation. If one skilled in the art, 
based on knowledge of compounds having similar 
physiological or biological activity, would be able to 
discern an appropriate dosage or method of use without 
undue experimentation, this would be sufficient to 
satisfy 35 U.S.C. 112, first paragraph.

When a compound or composition claim is limited 
by a particular use, enablement of that claim should 
be evaluated based on that limitation.

In contrast, when a compound or composition 
claim is not limited by a recited use, any enabled use 
that would reasonably correlate with the entire scope 
of that claim is sufficient to preclude a rejection for 
nonenablement based on how to use. If multiple uses 
for claimed compounds or compositions are disclosed 
in the application, then an enablement rejection must 
include an explanation, sufficiently supported by the 
evidence, why the specification fails to enable each 
disclosed use. In other words, if any use is enabled 
when multiple uses are disclosed, the application is 
enabling for the claimed invention.

===2164.02 Working Example===

Compliance with the enablement requirement of 
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. 

An applicant need not have actually reduced the 
invention to practice prior to filing. In Gould v. Quigg, 
822 F.2d 1074, 1078, 3 USPQ 2d 1302, 1304 (Fed. 
Cir. 1987), as of Gould’s filing date, no person had 
built a light amplifier or measured a population inversion 
in a gas discharge. The Court held that “The mere 
fact that something has not previously been done 
clearly is not, in itself, a sufficient basis for rejecting 
all applications purporting to disclose how to do it.” 
822 F.2d at 1078, 3 USPQ2d at 1304 (quoting In re 
Chilowsky, 229 F.2d 457, 461, 108 USPQ 321, 325 
(CCPA 1956)). 

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 reBorkowski, 422 F.2d 904, 908, 164 USPQ 642, 645 
(CCPA 1970). 

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. 

NONE OR ONE WORKING EXAMPLE

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.

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. 
To make a valid rejection, one 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.

CORRELATION: IN VITRO/IN VIVO

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 the 
PTO decision based on finding that in vitro data did 
not support in vivo applications).

Since the initial burden is on the examiner to give 
reasons for the lack of enablement, the examiner must 
also give reasons for a conclusion of lack of correlation 
for an in vitro or in vivo animal model example. 
A rigorous or an invariable exact correlation is not 
required, as stated in Cross v. Iizuka, 753 F.2d 1040, 
1050, 224 USPQ 739, 747 (Fed. Cir. 1985):

[B]ased upon the relevant evidence as a whole, there is a 
reasonable correlation between the disclosed in vitro utility 
and an in vivo activity, and therefore a rigorous correlation 
is not necessary where the disclosure of 
pharmacological activity is reasonable based upon the 
probative evidence. (Citations omitted.)

WORKING EXAMPLES AND A CLAIMED GENUS


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. 

===2164.03Relationship of Predictability of the Art and the Enablement Requirement===

The amount of guidance or direction needed to 
enable the invention is inversely related to the amount 
of knowledge in the state of the art as well as the predictability 
in the art. In re Fisher, 427 F.2d 833, 839, 
166 USPQ 18, 24 (CCPA 1970). The “amount of 
guidance or direction” refers to that information in the 
application, as originally filed, that teaches exactly 
how to make or use the invention. The more that is 
known in the prior art about the nature of the invention, 
how to make, and how to use the invention, and 
the more predictable the art is, the less information 
needs to be explicitly stated in the specification. In 
contrast, if little is known in the prior art about the 
nature of the invention and the art is unpredictable, 
the specification would need more detail as to how to 
make and use the invention in order to be enabling. 
See, e.g., Chiron Corp. v. Genentech Inc., 363 F.3d 
1247, 1254, 70 USPQ2d 1321, 1326 (Fed. Cir. 2004) 
(“Nascent technology, however, must be enabled with 
a ‘specific and useful teaching.’ The law requires an 
enabling disclosure for nascent technology because a 
person of ordinary skill in the art has little or no 
knowledge independent from the patentee’s instruction. 
Thus, the public’s end of the bargain struck by 
the patent system is a full enabling disclosure of the 
claimed technology.” (citations omitted)).

The “predictability or lack thereof” in the art refers 
to the ability of one skilled in the art to extrapolate the 
disclosed or known results to the claimed invention. If 
one skilled in the art can readily anticipate the effect 
of a change within the subject matter to which the 
claimed invention pertains, then there is predictability 
in the art. On the other hand, if one skilled in the art 
cannot readily anticipate the effect of a change within 
the subject matter to which that claimed invention 
pertains, then there is lack of predictability in the art. 
Accordingly, what is known in the art provides evidence 
as to the question of predictability. In particular, 
the court in In re Marzocchi, 439 F.2d 220, 223-24, 
169 USPQ 367, 369-70 (CCPA 1971), stated: 

[I]n the field of chemistry generally, there may be 
times when the well-known unpredictability of chemical 
reactions will alone be enough to create a reasonable 
doubt as to the accuracy of a particular broad statement 
put forward as enabling support for a claim. This will 
especially be the case where the statement is, on its face, 
contrary to generally accepted scientific principles. Most 
often, additional factors, such as the teachings in pertinent 
references, will be available to substantiate any doubts 
that the asserted scope of objective enablement is in fact 
commensurate with the scope of protection sought and to 
support any demands based thereon for proof. [Footnote 
omitted.]

The scope of the required enablement varies 
inversely with the degree of predictability involved, 
but even in unpredictable arts, a disclosure of every 
operable species is not required. A single embodiment 
may provide broad enablement in cases involving predictable 
factors, such as mechanical or electrical elements. 
In re Vickers, 141 F.2d 522, 526-27, 61 USPQ 
122, 127 (CCPA 1944); In re Cook, 439 F.2d 730, 
734, 169 USPQ 298, 301 (CCPA 1971). However, in 
applications directed to inventions in arts where the 
results are unpredictable, the disclosure of a single 
species usually does not provide an adequate basis to 





support generic claims. In re Soll, 97 F.2d 623, 624, 
38 USPQ 189, 191 (CCPA 1938). In cases involving 
unpredictable factors, such as most chemical reactions 
and physiological activity, more may be required. In 
re Fisher, 427 F.2d 833, 839, 166 USPQ 18, 24 
(CCPA 1970) (contrasting mechanical and electrical 
elements with chemical reactions and physiological 
activity). See also In re Wright, 999 F.2d 1557, 1562, 
27 USPQ2d 1510, 1513 (Fed. Cir. 1993); In re Vaeck, 
947 F.2d 488, 496, 20 USPQ2d 1438, 1445 (Fed. Cir. 
1991). This is because it is not obvious from the disclosure 
of one species, what other species will work. 

2164.04Burden on the Examiner Under 
the Enablement Requirement 
[R-1] [R-1]

Before any analysis of enablement can occur, it is 
necessary for the examiner to construe the claims. For 
terms that are not well-known in the art, or for terms 
that could have more than one meaning, it is necessary 
that the examiner select the definition that he/she 
intends to use when examining the application, based 
on his/her understanding of what applicant intends it 
to mean, and explicitly set forth the meaning of the 
term and the scope of the claim when writing an 
Office action. See Genentech v. Wellcome Foundation, 
29 F.3d 1555, 1563-64, 31 USPQ2d 1161, 1167-
68 (Fed. Cir. 1994).

In order to make a rejection, the examiner has the 
initial burden to establish a reasonable basis to question 
the enablement provided for the claimed invention. 
In re Wright, 999 F.2d 1557, 1562, 27 USPQ2d 
1510, 1513 (Fed. Cir. 1993) (examiner must provide a 
reasonable explanation as to why the scope of protection 
provided by a claim is not adequately enabled by 
the disclosure). A specification disclosure which contains 
a teaching of the manner and process of making 
and using an invention in terms which correspond in 
scope to those used in describing and defining the 
subject matter sought to be patented must be taken as 
being in compliance with the enablement requirement 
of 35 U.S.C. 112, first paragraph, unless there is a reason 
to doubt the objective truth of the statements contained 
therein which must be relied on for enabling 
support. Assuming that sufficient reason for such 
doubt exists, a rejection for failure to teach how to 
make and/or use will be proper on that basis. In reMarzocchi, 439 F.2d 220, 224, 169 USPQ 367, 370 
(CCPA 1971). As stated by the court, “it is incumbent 
upon the Patent Office, whenever a rejection on this 
basis is made, to explain why it doubts the truth or 
accuracy of any statement in a supporting disclosure 
and to back up assertions of its own with acceptable 
evidence or reasoning which is inconsistent with the 
contested statement. Otherwise, there would be no 
need for the applicant to go to the trouble and expense 
of supporting his presumptively accurate disclosure.” 
439 F.2d at 224, 169 USPQ at 370.

According to In re Bowen, 492 F.2d 859, 862-63, 
181 USPQ 48, 51 (CCPA 1974), the minimal requirement 
is for the examiner to give reasons for the uncertainty 
of the enablement. This standard is applicable 
even when there is no evidence in the record of operability 
without undue experimentation beyond the disclosed 
embodiments. See also In re Brana, 51 F.3d 
1560, 1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) 
(citing In re Bundy, 642 F.2d 430, 433, 209 USPQ 48, 
51 (CCPA 1981)) (discussed in MPEP § 2164.07regarding the relationship of the enablement requirement 
to the utility requirement of 35 U.S.C. 101). 

While the analysis and conclusion of a lack of 
enablement are based on the factors discussed in 
MPEP §
2164.01(a) and the evidence as a whole, it is 
not necessary to discuss each factor in the written 
enablement rejection. The language should focus on 
those factors, reasons, and evidence that lead the 
examiner to conclude that the specification fails to 
teach how to make and use the claimed invention 
without undue experimentation, or that the scope of 
any enablement provided to one skilled in the art is 
not commensurate with the scope of protection sought 
by the claims. This can be done by making specific 
findings of fact, supported by the evidence, and then 
drawing conclusions based on these findings of fact. 
For example, doubt may arise about enablement 
because information is missing about one or more 
essential parts or relationships between parts which 
one skilled in the art could not develop without undue 
experimentation. In such a case, the examiner should 
specifically identify what information is missing and 
why one skilled in the art could not supply the information 
without undue experimentation. See MPEP 
§
2164.06(a). References should be supplied if possible 
to support a prima facie case of lack of enablement, 
but are not always required. In re Marzocchi, 
439 F.2d 220, 224, 169 USPQ 367, 370 (CCPA 1971). 





However, specific technical reasons are always 
required.

In accordance with the principles of compact prosecution, 
if an enablement rejection is appropriate, the 
first Office action on the merits should present the 
best case with all the relevant reasons, issues, and evidence 
so that all such rejections can be withdrawn if 
applicant provides appropriate convincing arguments 
and/or evidence in rebuttal. Providing the best case in 
the first Office action will also allow the second 
Office action to be made final should applicant fail to 
provide appropriate convincing arguments and/or evidence. 
Citing new references and/or expanding arguments 
in a second Office action could prevent that 
Office action from being made final. The principles of 
compact prosecution also dictate that if an enablement 
rejection is appropriate and the examiner recognizes 
limitations that would render the claims enabled, the 
examiner should note such limitations to applicant as 
early in the prosecution as possible. 

In other words, the examiner should always look 
for enabled, allowable subject matter and communicate 
to applicant what that subject matter is at the earliest 
point possible in the prosecution of the 
application.

2164.05Determination of Enablement 
Based on Evidence as a Whole

Once the examiner has weighed all the evidence 
and established a reasonable basis to question the 
enablement provided for the claimed invention, the 
burden falls on applicant to present persuasive arguments, 
supported by suitable proofs where necessary, 
that one skilled in the art would be able to make and 
use the claimed invention using the application as a 
guide. In re Brandstadter, 484 F.2d 1395, 1406-07, 
179 USPQ 286, 294 (CCPA 1973). The evidence provided 
by applicant need not be conclusive but merely 
convincing to one skilled in the art. 

Applicant may submit factual affidavits under 37 
CFR 1.132 or cite references to show what one skilled 
in the art knew at the time of filing the application. A 
declaration or affidavit is, itself, evidence that must be 
considered. The weight to give a declaration or affidavit 
will depend upon the amount of factual evidence 
the declaration or affidavit contains to support the 
conclusion of enablement. In re Buchner, 929 F.2d 
660, 661, 18 USPQ2d 1331, 1332 (Fed. Cir. 1991) 
(“expert’s opinion on the ultimate legal conclusion 
must be supported by something more than a conclusory 
statement”); cf. In re Alton, 76 F.3d 1168, 1174, 
37 USPQ2d 1578, 1583 (Fed. Cir. 1996) (declarations 
relating to the written description requirement should 
have been considered).

Applicant should be encouraged to provide any evidence 
to demonstrate that the disclosure enables the 
claimed invention. In chemical and biotechnical 
applications, evidence actually submitted to the FDA 
to obtain approval for clinical trials may be submitted. 
However, considerations made by the FDA for 
approving clinical trials are different from those made 
by the PTO in determining whether a claim is enabled. 
See Scott v. Finney, 34 F.3d 1058, 1063, 32 USPQ2d 
1115, 1120 (Fed. Cir. 1994) (“Testing for full safety 
and effectiveness of a prosthetic device is more properly 
left to the [FDA].”). Once that evidence is submitted, 
it must be weighed with all other evidence 
according to the standards set forth above so as to 
reach a determination as to whether the disclosure 
enables the claimed invention. 

To overcome a prima facie case of lack of enablement, 
applicant must demonstrate by argument and/or 
evidence that the disclosure, as filed, would have 
enabled the claimed invention for one skilled in the 
art at the time of filing. This does not preclude applicant 
from providing a declaration after the filing date 
which demonstrates that the claimed invention works. 
However, the examiner should carefully compare the 
steps, materials, and conditions used in the experiments 
of the declaration with those disclosed in the 
application to make sure that they are commensurate 
in scope; i.e., that the experiments used the guidance 
in the specification as filed and what was well known 
to one of skill in the art. Such a showing also must be 
commensurate with the scope of the claimed invention, 
i.e., must bear a reasonable correlation to the 
scope of the claimed invention. 

The examiner must then weigh all the evidence 
before him or her, including the specification and any 
new evidence supplied by applicant with the evidence 
and/or sound scientific reasoning previously presented 
in the rejection and decide whether the claimed 
invention is enabled. The examiner should nevermake the determination based on personal opinion. 
The determination should always be based on the 
weight of all the evidence.





2164.05(a)Specification Must Be Enabling 
as of the Filing Date [R-2]

Whether the specification would have been 
enabling as of the filing date involves consideration of 
the nature of the invention, the state of the prior art, 
and the level of skill in the art. The initial inquiry is 
into the nature of the invention, i.e., the subject matter 
to which the claimed invention pertains. The nature of 
the invention becomes the backdrop to determine the 
state of the art and the level of skill possessed by one 
skilled in the art. 

The state of the prior art is what one skilled in the 
art would have known, at the time the application was 
filed, about the subject matter to which the claimed 
invention pertains. The relative skill of those in the art 
refers to the skill of those in the art in relation to the 
subject matter to which the claimed invention pertains 
at the time the application was filed. See MPEP 
§
2164.05(b).

The state of the prior art provides evidence for the 
degree of predictability in the art and is related to the 
amount of direction or guidance needed in the specification 
as filed to meet the enablement requirement. 
The state of the prior art is also related to the need for 
working examples in the specification. 

The state of the art for a given technology is not 
static in time. It is entirely possible that a disclosure 
filed on January 2, 1990, would not have been 
enabled. However, if the same disclosure had been 
filed on January 2, 1996, it might have enabled the 
claims. Therefore, the state of the prior art must be 
evaluated for each application based on its filing date.

35 U.S.C. 112 requires the specification to be 
enabling only to a person “skilled in the art to which it 
pertains, or with which it is most nearly connected.” 
In general, the pertinent art should be defined in terms 
of the problem to be solved rather than in terms of the 
technology area, industry, trade, etc. for which the 
invention is used. 

The specification need not disclose what is well-
known to those skilled in the art and preferably omits 
that which is well-known to those skilled and already 
available to the public. In re Buchner, 929 F.2d 660, 
661, 18 USPQ2d 1331, 1332 (Fed. Cir. 1991); 
Hybritech, Inc. v. Monoclonal Antibodies, Inc., 
802 
F.2d 1367, 1384, 231 USPQ 81, 94 (Fed. Cir. 
1986), cert. denied, 480 U.S. 947 (1987); and Lindemann 
Maschinenfabrik GMBH v. American Hoist & 
Derrick Co., 730 F.2d 1452, 1463, 221 USPQ 481, 
489 (Fed. Cir. 1984). 

The state of the art existing at the filing date of the 
application is used to determine whether a particular 
disclosure is enabling as of the filing date. Chiron 
Corp. v. Genentech Inc., 363 F.3d 1247, 1254, 70 
USPQ2d 1321, 1325-26 (Fed. Cir. 2004) (“a patent 
document cannot enable technology that arises after 
the date of application”). Publications dated after the 
filing date providing information publicly first disclosed 
after the filing date generally cannot be used to 
show what was known at the time of filing. In reGunn, 537 F.2d 1123, 1128, 190 USPQ 402,405-06 
(CCPA 1976); In re Budnick, 537 F.2d 535, 538, 190 
USPQ 422, 424 (CCPA 1976) (In general, if an applicant 
seeks to use a patent to prove the state of the art 
for the purpose of the enablement requirement, the 
patent must have an issue date earlier than the effective 
filing date of the application.). While a later dated 
publication cannot supplement an insufficient disclosure 
in a prior dated application to make it enabling, 
applicant can offer the testimony of an expert based 
on the publication as evidence of the level of skill in 
the art at the time the application was filed. Gould v.
Quigg, 822 F.2d 1074, 1077, 3 
USPQ2d 1302, 1304 
(Fed. Cir. 1987). 

In general, the examiner should not use post-filing 
date references to demonstrate that the patent is non-
enabling. Exceptions to this rule could occur if a later-
dated reference provides evidence of what one skilled 
in the art would have known on or before the effective 
filing date of the patent application. In re Hogan, 559 
F.2d 595, 605, 194 USPQ 527, 537 (CCPA 1977). If 
individuals of skill in the art state that a particular 
invention is not possible years after the filing date, 
that would be evidence that the disclosed invention 
was not possible at the time of filing and should be 
considered. In In re Wright, 999 F.2d 1557, 1562, 27 
USPQ2d 1510, 1513-14 (Fed. Cir. 1993) an article 
published 5 years after the filing date of the application 
adequately supported the examiner’s position that 
the physiological activity of certain viruses was sufficiently 
unpredictable so that a person skilled in the art 
would not have believed that the success with one 
virus and one animal could be extrapolated successfully 
to all viruses with all living organisms. Claims 





not directed to the specific virus and the specific animal 
were held nonenabled.

2164.05(b)Specification Must Be Enabling 
to Persons Skilled in the Art

The relative skill of those in the art refers to the 
skill of those in the art in relation to the subject matter 
to which the claimed invention pertains at the time the 
application was filed. Where different arts are 
involved in the invention, the specification is enabling 
if it enables persons skilled in each art to carry out the 
aspect of the invention applicable to their specialty. In 
re Naquin, 398 F.2d 863, 866, 158 USPQ 317, 319 
(CCPA 1968).

When an invention, in its different aspects, involves 
distinct arts, the specification is enabling if it enables 
those skilled in each art, to carry out the aspect proper 
to their specialty. “If two distinct technologies are relevant 
to an invention, then the disclosure will be adequate 
if a person of ordinary skill in each of the two 
technologies could practice the invention from the 
disclosures.” Technicon Instruments Corp. v. Alpkem 
Corp., 664 F. Supp. 1558, 1578, 2 USPQ2d 1729, 
1742 (D. Ore. 1986), aff’d in part, vacated in part, 
rev’d in part, 837 F. 2d 1097 (Fed. Cir. 1987) (unpublished 
opinion), appeal after remand, 866 F. 2d 417, 
9 
USPQ 2d 1540 (Fed. Cir. 1989). In Ex parte Zechnall, 
194 USPQ 461 (Bd. App. 1973), the Board 
stated “appellants’ disclosure must be held sufficient 
if it would enable a person skilled in the electronic 
computer art, in cooperation with a person skilled in 
the fuel injection art, to make and use appellants’ 
invention.” 194 USPQ at 461.

2164.06Quantity of Experimentation

The quantity of experimentation needed to be performed 
by one skilled in the art is only one factor 
involved in determining whether “undue experimentation” 
is required to make and use the invention. “[A]n 
extended period of experimentation may not be undue 
if the skilled artisan is given sufficient direction or 
guidance.” In re Colianni, 561 F.2d 220, 224, 
195 
USPQ 150, 153 (CCPA 1977). “ ‘The test is not 
merely quantitative, since a considerable amount of 
experimentation is permissible, if it is merely routine, 
or if the specification in question provides a reasonable 
amount of guidance with respect to the direction 
in which the experimentation should proceed.’” In re 
Wands, 858 F.2d 731, 737, 8 USPQ2d 1400, 1404 
(Fed. Cir. 1988) (citing In re Angstadt, 537 F.2d 489, 
502-04, 190 USPQ 214, 217-19 (CCPA 1976)). Time 
and expense are merely factors in this consideration 
and are not the controlling factors. United States v. 
Telectronics Inc., 857 F.2d 778, 785, 8 USPQ2d 1217, 
1223 (Fed. Cir. 1988), cert. denied, 490 U.S. 1046 
(1989).

In the chemical arts, the guidance and ease in carrying 
out an assay to achieve the claimed objectives 
may be an issue to be considered in determining the 
quantity of experimentation needed. For example, if a 
very difficult and time consuming assay is needed to 
identify a compound within the scope of a claim, then 
this great quantity of experimentation should be considered 
in the overall analysis. Time and difficulty of 
experiments are not determinative if they are merely 
routine. Quantity of examples is only one factor that 
must be considered before reaching the final conclusion 
that undue experimentation would be required. In 
re Wands, 858 F.2d at 737, 8 USPQ2d at 1404. 

I.EXAMPLE OF REASONABLE EXPERIMENTATION


In United States v. Telectronics, Inc., 857 F.2d 778, 
8 USPQ2d 1217 (Fed. Cir. 1988), cert. denied, 
490 
U.S. 1046 (1989), the court reversed the findings 
of the district court for lack of clear and convincing 
proof that undue experimentation was needed. The 
court ruled that since one embodiment (stainless steel 
electrodes) and the method to determine dose/
response was set forth in the specification, the specification 
was enabling. The question of time and 
expense of such studies, approximately $50,000 and 
6-12 months standing alone, failed to show undue 
experimentation.

II.EXAMPLE OF UNREASONABLE EXPERIMENTATION


In In re Ghiron, 442 F.2d 985, 991-92, 169 USPQ 
723, 727-28 (CCPA 1971), functional “block diagrams” 
were insufficient to enable a person skilled in 
the art to practice the claimed invention with only a 
reasonable degree of experimentation because the 
claimed invention required a “modification to prior 
art overlap computers,” and because “many of the 
components which appellants illustrate as rectangles 
in their drawing necessarily are themselves complex 





assemblages . . . . It is common knowledge that many 
months or years elapse from the announcement of a 
new computer by a manufacturer before the first prototype 
is available. This does not bespeak of a routine 
operation but of extensive experimentation and development 
work. . . .” 

2164.06(a)Examples of Enablement 
Issues-Missing Information 
[R-1] [R-1]

It is common that doubt arises about enablement 
because information is missing about one or more 
essential parts or relationships between parts which 
one skilled in the art could not develop without undue 
experimentation. In such a case, the examiner should 
specifically identify what information is missing and 
why the missing information is needed to provide 
enablement.

I.ELECTRICAL AND MECHANICAL DEVICES 
OR PROCESSES

For example, a disclosure of an electrical circuit 
apparatus, depicted in the drawings by block diagrams 
with functional labels, was held to be nonenabling in 
In re Gunn, 537 F.2d 1123, 1129, 190 USPQ 402, 406 
(CCPA 1976). There was no indication in the specification 
as to whether the parts represented by boxes 
were “off the shelf” or must be specifically constructed 
or modified for applicant’s system. Also there 
were no details in the specification of how the parts 
should be interconnected, timed and controlled so as 
to obtain the specific operations desired by the applicant. 
In In re Donohue, 550 F.2d 1269, 193 USPQ 136 
(CCPA 1977), the lack of enablement was caused by 
lack of information in the specification about a single 
block labelled “LOGIC” in the drawings. See also 
Union Pacific Resources Co. v. Chesapeake Energy 
Corp., 236 F.3d 684, 57 USPQ2d 1293 (Fed. Cir. 
2001) (Claims directed to a method of determining 
the location of a horizontal borehole in the earth failed 
to comply with enablement requirement of 35 U.S.C. 
112 because certain computer programming details 
used to perform claimed method were not disclosed in 
the specification, and the record showed that a person 
of skill in art would not understand how to “compare” 
or “rescale” data as recited in the claims in order to 
perform the claimed method.).

In re Ghiron, 442 F.2d 985, 169 USPQ 723 (CCPA 
1971), involved a method of facilitating transfers 
from one subset of program instructions to another 
which required modification of prior art “overlap 
mode” computers. The Board rejected the claims on 
the basis, inter alia, that the disclosure was insufficient 
to satisfy the requirements of 35 U.S.C. 112, 
first paragraph and was affirmed. The Board focused 
on the fact that the drawings were “block diagrams, 
i.e., a group of rectangles representing the elements of 
the system, functionally labelled and interconnected 
by lines.” 442 F.2d at 991, 169 USPQ at 727. The 
specification did not particularly identify each of the 
elements represented by the blocks or the relationship 
therebetween, nor did it specify particular apparatus 
intended to carry out each function. The Board further 
questioned whether the selection and assembly of the 
required components could be carried out routinely by 
persons of ordinary skill in the art.

An adequate disclosure of a device may require 
details of how complex components are constructed 
and perform the desired function. The claim before 
the court in In re Scarbrough, 500 F.2d 560, 182 
USPQ 298 (CCPA 1974) was directed to a system 
which comprised several component parts (e.g., computer, 
timing and control mechanism, A/D converter, 
etc.) only by generic name and overall ultimate function. 
The court concluded that there was not an 
enabling disclosure because the specification did not 
describe how “complex elements known to perform 
broadly recited functions in different systems would 
be adaptable for use in Appellant’s particular system 
with only a reasonable amount of experimentation” 
and that “an unreasonable amount of work would be 
required to arrive at the detailed relationships appellant 
says that he has solved.” 500 F.2d at 566, 
182 
USPQ at 302.

II.MICROORGANISMS

Patent applications involving living biological 
products, such as microorganisms, as critical elements 
in the process of making the invention, present a 
unique question with regard to availability. The issue 
was raised in a case involving claims drawn to a fermentative 
method of producing two novel antibiotics 
using a specific microorganism and claims to the 
novel antibiotics so produced. In re Argoudelis, 
434 
F.2d 1390, 168 USPQ 99 (CCPA 1970). As stated 





by the court, “a unique aspect of using microorganisms 
as starting materials is that a sufficient description 
of how to obtain the microorganism from nature 
cannot be given.” 434 F.2d at 1392, 168 USPQ at 102. 
It was determined by the court that availability of the 
biological product via a public depository provided an 
acceptable means of meeting the written description 
and the enablement requirements of 35 U.S.C. 112, 
first paragraph.

To satisfy the enablement requirement a deposit 
must be made “prior to issue” but need not be made 
prior to filing the application. In re Lundak, 773 F.2d 
1216, 1223, 227 USPQ 90, 95 (Fed. Cir. 1985).

The availability requirement of enablement must 
also be considered in light of the scope or breadth of 
the claim limitations. The Board of Appeals considered 
this issue in an application which claimed a fermentative 
method using microorganisms belonging to 
a species. Applicants had identified three novel individual 
strains of microorganisms that were related in 
such a way as to establish a new species of microorganism, 
a species being a broader classification than a 
strain. The three specific strains had been appropriately 
deposited. The issue focused on whether the 
specification enabled one skilled in the art to make 
any member of the species other than the three strains 
which had been deposited. The Board concluded that 
the verbal description of the species was inadequate to 
allow a skilled artisan to make any and all members of 
the claimed species. Ex parte Jackson, 217 USPQ 
804, 806 (Bd. App. 1982). 

See MPEP § 2402 - § 2411.03 for a detailed discussion 
of the deposit rules. See MPEP § 2411.01 for 
rejections under 35 U.S.C. 112 based on deposit 
issues.

III.DRUG CASES

See MPEP § 2107 - § 2107.03 for a discussion of 
the utility requirement under 35 U.S.C. 112, first paragraph, 
in drug cases.

2164.06(b)Examples of Enablement Issues 
— Chemical Cases

The following summaries should not be relied on to 
support a case of lack of enablement without carefully 
reading the case.

SEVERAL DECISIONS RULING THAT THE 
DISCLOSURE WAS NONENABLING 

(A)In Enzo Biochem, Inc. v. Calgene, Inc., 
188 
F.3d 1362, 52 USPQ2d 1129 (Fed. Cir. 1999), the 
court held that claims in two patents directed to 
genetic antisense technology (which aims to control 
gene expression in a particular organism), were 
invalid because the breadth of enablement was not 
commensurate in scope with the claims. Both specifications 
disclosed applying antisense technology in 
regulating three genes in E. coli. Despite the limited 
disclosures, the specifications asserted that the “[t]he 
practices of this invention are generally applicable 
with respect to any organism containing genetic material 
which is capable of being expressed … such as 
bacteria, yeast, and other cellular organisms.” The 
claims of the patents encompassed application of antisense 
methodology in a broad range of organisms. 
Ultimately, the court relied on the fact that (1) the 
amount of direction presented and the number of 
working examples provided in the specification were 
very narrow compared to the wide breadth of the 
claims at issue, (2) antisense gene technology was 
highly unpredictable, and (3) the amount of experimentation 
required to adapt the practice of creating 
antisense DNA from E. coli to other types of cells was 
quite high, especially in light of the record, which 
included notable examples of the inventor’s own failures 
to control the expression of other genes in E. coliand other types of cells. Thus, the teachings set forth 
in the specification provided no more than a “plan” or 
“invitation” for those of skill in the art to experiment 
using the technology in other types of cells. 

(B)In In re Wright, 999 F.2d 1557, 27 USPQ2d 
1510 (Fed. Cir. 1993), the 1983 application disclosed 
a vaccine against the RNA tumor virus known as Prague 
Avian Sarcoma Virus, a member of the Rous 
Associated Virus family. Using functional language, 
Wright claimed a vaccine “comprising an immunologically 
effective amount” of a viral expression product. 
Id., at 1559, 27 USPQ2d at 1511. Rejected claims 
covered all RNA viruses as well as avian RNA 
viruses. The examiner provided a teaching that in 
1988, a vaccine for another retrovirus (i.e., AIDS) 
remained an intractable problem. This evidence, along 
with evidence that the RNA viruses were a diverse 
and complicated genus, convinced the Federal Circuit 





that the invention was not enabled for either all retroviruses 
or even for avian retroviruses.

(C)In In re Goodman, 11 F.3d 1046, 29 USPQ2d 
2010 (Fed. Cir. 1993), a 1985 application functionally 
claimed a method of producing protein in plant cells 
by expressing a foreign gene. The court stated: 
“[n]aturally, the specification must teach those of skill 
in the art ‘how to make and use the invention as 
broadly as it is claimed.’” Id. at 1050, 29 USPQ2d at 
2013. Although protein expression in dicotyledonous 
plant cells was enabled, the claims covered any plant 
cell. The examiner provided evidence that even as late 
as 1987, use of the claimed method in monocot plant 
cells was not enabled. Id. at 1051, 29 USPQ2d at 
2014.

(D)In In re Vaeck, 947 F.2d 488, 495, 
20 
USPQ2d 1438, 1444 (Fed. Cir. 1991), the court 
found that several claims were not supported by an 
enabling disclosure “[t]aking into account the relatively 
incomplete understanding of the biology of 
cyanobacteria as of appellants’ filing date, as well as 
the limited disclosure by appellants of the particular 
cyanobacterial genera operative in the claimed invention....” 
The claims at issue were not limited to any 
particular genus or species of cyanobacteria and the 
specification mentioned nine genera and the working 
examples employed one species of cyanobacteria.

(E)In In re Colianni, 561 F.2d 220, 222-23, 
195 
USPQ 150, 152 (CCPA 1977), the court affirmed 
a rejection under 35 U.S.C. 112, first paragraph, 
because the specification, which was directed to a 
method of mending a fractured bone by applying 
“sufficient” ultrasonic energy to the bone, did not 
define a “sufficient” dosage or teach one of ordinary 
skill how to select the appropriate intensity, frequency, 
or duration of the ultrasonic energy. 

SEVERAL DECISIONS RULING THAT THE 
DISCLOSURE WAS ENABLING 

(A)In PPG Ind. v. Guardian Ind., 75 F.3d 1558, 
1564, 37 USPQ2d 1618, 1623 (Fed. Cir. 1996), the 
court ruled that even though there was a software 
error in calculating the ultraviolet transmittance data 
for examples in the specification making it appear that 
the production of a cerium oxide-free glass that satisfied 
the transmittance limitation would be difficult, 
the specification indicated that such glass could be 
made. The specification was found to indicate how to 
minimize the cerium content while maintaining low 
ultraviolet transmittance. 

(B)In In re Wands, 858 F.2d 731, 8 USPQ2d 
1400 (Fed. Cir. 1988), the court reversed the rejection 
for lack of enablement under 35 U.S.C. 112, first 
paragraph, concluding that undue experimentation 
would not be required to practice the invention. The 
nature of monoclonal antibody technology is such that 
experiments first involve the entire attempt to make 
monoclonal hybridomas to determine which ones 
secrete antibody with the desired characteristics. The 
court found that the specification provided considerable 
direction and guidance on how to practice the 
claimed invention and presented working 
examples,
that all of the methods needed to practice 
the invention were well known, and that there was a 
high level of skill in the art at the time the application 
was filed. Furthermore, the applicant carried out the 
entire procedure for making a monoclonal antibody 
against HBsAg three times and each time was successful 
in producing at least one antibody which fell 
within the scope of the claims.

(C)In In re Bundy, 642 F.2d 430, 434, 209 USPQ 
48, 51-52 (CCPA 1981), the court ruled that appellant’s 
disclosure was sufficient to enable one skilled in 
the art to use the claimed analogs of naturally occurring 
prostaglandins even though the specification 
lacked any examples of specific dosages, because the 
specification taught that the novel prostaglandins had 
certain pharmacological properties and possessed 
activity similar to known E-type prostaglandins.



2164.06(c)Examples of Enablement Issues 
– Computer Programming Cases[R-5]

To establish a reasonable basis for questioning the 
adequacy of a disclosure, the examiner must present a 
factual analysis of a disclosure to show that a person 
skilled in the art would not be able to make and use 
the claimed invention without resorting to undue 
experimentation.

In computer applications, it is not unusual for the 
claimed invention to involve two areas of prior art or 
more than one technology, e.g., an appropriately programmed 
computer and an area of application of said 
computer. White Consol. Indus. v. Vega Servo-Control, 
Inc., 214 USPQ 796, 821 (S.D.Mich. 1982). In 





regard to the “skilled in the art” standard, in cases 
involving both the art of computer programming, and 
another technology, the examiner must recognize that 
the knowledge of persons skilled in both technologies 
is the appropriate criteria for determining sufficiency. 
See In re Naquin, 398 F.2d 863, 158 USPQ 317 
(CCPA 1968); In re Brown, 477 F.2d 946, 177 USPQ 
691 (CCPA 1973); White Consol. Indus., 214 USPQ 
at 822, aff’d on related grounds, 713 F.2d 788, 
218 
USPQ 961 (Fed. Cir. 1983).

In a typical computer application, system components 
are often represented in a “block diagram” format, 
i.e., a group of hollow rectangles representing 
the elements of the system, functionally labeled, and 
interconnected by lines. Such block diagram computer 
cases may be categorized into (A) systems 
which include but are more comprehensive than a 
computer and (B) systems wherein the block elements 
are totally within the confines of a computer.

I.BLOCK ELEMENTS MORE COMPREHENSIVE 
THAN A COMPUTER

The first category of such block diagram cases 
involves systems which include a computer as well as 
other system hardware and/or software components. 
In order to meet his or her burden of establishing a 
reasonable basis for questioning the adequacy of such 
disclosure, the examiner should initiate a factual analysis 
of the system by focusing on each of the individual 
block element components. More specifically, 
such an inquiry should focus on the diverse functions 
attributed to each block element as well as the teachings 
in the specification as to how such a component 
could be implemented. If based on such an analysis, 
the examiner can reasonably contend that more than 
routine experimentation would be required by one of 
ordinary skill in the art to implement such a component 
or components, that component or components 
should specifically be challenged by the examiner as 
part of a 35 U.S.C. 112, first paragraph rejection. 
Additionally, the examiner should determine whether 
certain of the hardware or software components 
depicted as block elements are themselves complex 
assemblages which have widely differing characteristics 
and which must be precisely coordinated with 
other complex assemblages. Under such circumstances, 
a reasonable basis may exist for challenging 
such a functional block diagram form of disclosure. 
See In re Ghiron, 442 F.2d 985, 169 USPQ 723 
(CCPA 1971) and In re Brown, supra. Moreover, even 
if the applicant has cited prior art patents or publications 
to demonstrate that particular block diagram 
hardware or software components are old, it should 
not always be considered as self-evident how such 
components are to be interconnected to function in a 
disclosed complex manner. See In re Scarbrough, 
500 
F.2d 560, 566, 182 USPQ 298, 301 (CCPA 1974) 
and In re Forman, 463 F.2d 1125, 1129, 175 USPQ 
12, 16 (CCPA 1972). Furthermore, in complex systems 
including a digital computer, a microprocessor, 
or a complex control unit as one of many block diagram 
elements, timing between various system elements 
may be of the essence and without a timing 
chart relating the timed sequences for each element, 
an unreasonable amount of work may be required to 
come up with the detailed relationships an applicant 
alleges that he or she has solved. See In re Scarbrough, 
500 F.2d at 566, 182 USPQ at 302.

For example, in a block diagram disclosure of a 
complex claimed system which includes a microprocessor 
and other system components controlled by 
the 
microprocessor, a mere reference to a prior art, 
commercially available microprocessor, without 
any 
description of the precise operations to be performed 
by the microprocessor, fails to disclose how 
such a microprocessor would be properly programmed 
to 
either perform any required calculations 
or to coordinate the other system components in 
the 
proper timed sequence to perform the functions 
disclosed and claimed. If, in such a system, a particular 
program is disclosed, such a program should be 
carefully reviewed to ensure that its scope is commensurate 
with the scope of the functions attributed to 
such a program in the claims. See In re Brown, 477 
F.2d at 951, 177 USPQ at 695. If the disclosure fails 
to disclose any program and if more than routine 
experimentation would be required of one skilled in 
the art to generate such a program, the examiner 
clearly would have a reasonable basis for challenging 
the sufficiency of such a disclosure. The amount of 
experimentation that is considered routine will vary 
depending on the facts and circumstances of individual 
cases. No exact numerical standard has been fixed 
by the courts, but the “amount of required experimentation 
must, however, be reasonable.” White Consol. 
Indus., 713 F.2d at 791, 218 USPQ at 963. One court 





apparently found that the amount of experimentation 
involved was reasonable where a skilled programmer 
was able to write a general computer program, implementing 
an embodiment form, within 4 hours. Hirschfield 
v. Banner, 462 F. Supp. 135, 142, 200 USPQ 
276, 279 (D.D.C. 1978), aff’d, 615 F.2d 1368 (D.C. 
Cir. 1986), cert. denied, 450 U.S. 994 (1981). Another 
court found that, where the required period of experimentation 
for skilled programmers to develop a particular 
program would run to 1 to 2 man years, this 
would be “a clearly unreasonable requirement” (White 
Consol. Indus., 713 F.2d at 791, 218 USPQ at 963).

II.BLOCK ELEMENTS WITHIN A COMPUTER


The second category of block diagram cases occurs 
most frequently in pure data processing applications 
where the combination of block elements is totally 
within the confines of a computer, there being no 
interfacing with external apparatus other than normal 
input/output devices. In some instances, it has been 
found that particular kinds of block diagram disclosures 
were sufficient to meet the enabling requirement 
of 35 U.S.C. 112, first paragraph. See In re Knowlton, 
481 F.2d 1357, 178 USPQ 486 (CCPA 1973), In re 
Comstock, 481 F.2d 905, 178 USPQ 616 (CCPA 
1973). Most significantly, however, in both the Comstock 
and Knowlton cases, the decisions turned on the 
appellants’ disclosure of (A) a reference to and reliance 
on an identified prior art computer system and 
(B) an operative computer program for the referenced 
prior art computer system. Moreover, in Knowlton the 
disclosure was presented in such a detailed fashion 
that the individual program's steps were specifically 
interrelated with the operative structural elements in 
the referenced prior art computer system. The court in 
Knowlton indicated that the disclosure did not merely 
consist of a sketchy explanation of flow diagrams or a 
bare group of program listings together with a reference 
to a proprietary computer in which they might be 
run. The disclosure was characterized as going into 
considerable detail in explaining the interrelationships 
between the disclosed hardware and software elements. 
Under such circumstances, the Court considered 
the disclosure to be concise as well as full, clear, 
and exact to a sufficient degree to satisfy the literal 
language of 35 U.S.C. 112, first paragraph. It must be 
emphasized that because of the significance of the 
program listing and the reference to and reliance on 
an identified prior art computer system, absent either 
of these items, a block element disclosure within the 
confines of a computer should be scrutinized in precisely 
the same manner as the first category of block 
diagram cases discussed above.

Regardless of whether a disclosure involves block 
elements more comprehensive than a computer or 
block elements totally within the confines of a computer, 
USPTO personnel, when analyzing method 
claims, must recognize that the specification must be 
adequate to teach how to practice the claimed method. 
If such practice requires a particular apparatus, then 
the application must provide a sufficient disclosure of 
that apparatus if such is not already available. See In 
re Ghiron, 442 F.2d 985, 991, 169 USPQ 723, 727 
(CCPA 1971) and In re Gunn, 537 F.2d 1123, 1128, 
190 USPQ 402, 406 (CCPA 1976). When USPTO 
personnel question the adequacy of computer system 
or computer programming disclosures, the reasons for 
finding the specification to be nonenabling should be 
supported by the record as a whole. In this regard, it is 
also 
essential for USPTO personnel to reasonably 
challenge evidence submitted by the applicant. For 
example, in In re Naquin, supra, an affiant’s statement 
that the average computer programmer was familiar 
with the subroutine necessary for performing the 
claimed process, was held to be a 
statement of fact as 
it was unchallenged by USPTO personnel. In other 
words, unless USPTO personnel present a reasonable 
basis for challenging the disclosure in view of the 
record as a whole, a 35 U.S.C. 112, first paragraph 
rejection in a computer system or computer programming 
application may not be sustained on appeal. See 
In re Naquin, supra, and In re Morehouse, 545 F.2d 
162, 165-66, 192 USPQ 29, 32 
(CCPA 1976).

While no specific universally applicable rule exists 
for recognizing an insufficiently disclosed application 
involving computer programs, an examining guideline 
to generally follow is to challenge the sufficiency 
of such disclosures which fail to include either the 
computer program itself or a reasonably detailed 
flowchart which delineates the sequence of operations 
the program must perform. In programming applications 
where the software disclosure only includes a 
flowchart, as the complexity of functions and the generality 
of the individual components of the flowchart 
increase, the basis for challenging the sufficiency of 





such a flowchart becomes more reasonable because 
the likelihood of more than routine experimentation 
being required to generate a working program from 
such a flowchart also increases.

As stated earlier, once USPTO personnel have 
advanced a reasonable basis or presented evidence to 
question the adequacy of a computer system or computer 
programming disclosure, the applicant must 
show that his or her specification would enable one of 
ordinary skill in the art to make and use the claimed 
invention without resorting to undue experimentation. 
In most cases, efforts to meet this burden involve submitting 
affidavits, referencing prior art patents or 
technical publications, presenting arguments of counsel, 
or combinations of these approaches.

III.AFFIDAVIT PRACTICE (37 CFR 1.132)

In computer cases, affidavits must be critically analyzed. 
Affidavit practice at the outset usually involves 
analyzing the skill level and/or qualifications of the 
affiant, which should be of the person of ordinary skill 
in the art (hereinafter “routineer”). When an affiant’s 
skill level is 
higher than that required by the routineer 
for a particular application, an examiner may challenge 
the affidavit since 
it would not be made by a 
routineer in the art, and therefore would not be probative 
as to the amount of experimentation required by a 
routineer in the art to implement the invention. An 
affiant having a skill level or qualifications above that 
of the routineer in the art would require less experimentation 
to implement the claimed invention than 
that for the routineer. Similarly, an affiant having a 
skill level or qualifications below that of the routineer 
in the art would require more experimentation to 
implement the claimed invention than that for the routineer 
in the art. In either situation, the standard of the 
routineer in the art would not have been met.

In computer systems or programming cases, the 
problems with a given affidavit, which relate to the 
sufficiency of disclosure issue, generally involve affiants 
submitting few facts to support their conclusions 
or opinions. Some affidavits may go so far as to 
present conclusions on the ultimate legal question of 
sufficiency. In re Brandstadter, 484 F.2d 1395,179 
USPQ 286 (CCPA 1973), illustrates the extent of 
the inquiry into the factual basis underlying an affiant’s 
conclusions or opinions. In Brandstadter, the 
invention concerned a stored program controller 
(computer) programmed to control the storing, 
retrieving, and forwarding of messages in a communications 
system. The disclosure consisted of broadly 
defined block diagrams of the structure of the invention 
and no flowcharts or program listings of the programs 
of the controller. The Court quoted extensively 
from the Examiner’s Office Actions and Examiner’s 
Answer in its opinion where it was apparent that the 
Examiner consistently argued that the disclosure was 
merely a broad system diagram in the form of labelled 
block diagrams along with statements of a myriad of 
desired results. Various affidavits were presented in 
which the affiants stated that all or some of the system 
circuit elements in the block diagrams were either 
well-known in the art or “could be constructed” by the 
skilled design engineer, that the controller was “capable 
of being programmed” to perform the stated functions 
or results desired, and that the routineer in the art 
“could design or construct or was able to program” 
the system. The Court did consider the affiants’ statements 
as being some evidence on the ultimate 
legal 
question of enablement but concluded that the 
statements failed in their purpose since they recited 
conclusions or opinions with few facts to support or 
buttress these conclusions. With reference to the 
lack 
of a disclosed computer program or even a flowchart 
of the program to control the message switching 
system, the record contained no evidence as to 
the 
number of programmers needed, the number of 
man-hours and the level of skill of the programmers 
to produce the program required to practice the invention.


It should be noted also that it is not opinion evidence 
directed to the ultimate legal question of 
enablement, but rather factual evidence directed to the 
amount of time and effort and level of knowledge 
required for the practice of the invention from the disclosure 
alone which can be expected to rebut a prima 
facie case of nonenablement. See Hirschfield, 462 F. 
Supp. at 143, 200 USPQ at 281. It has also been held 
that where an inventor described the problem to be 
solved to an affiant, thus enabling the affiant to generate 
a computer program to solve the problem, such an 
affidavit failed to demonstrate that the application 
alone would have taught a person of ordinary skill in 
the art how to make and use the claimed invention. 
See In re Brown, 477 F.2d at 951, 177 USPQ at 
695.
The Court indicated that it was not factually 





established that the applicant did not convey to the 
affiant vital and additional information in their several 
meetings in addition to that set out in the application. 
Also of significance for an affidavit to be relevant to 
the determination of enablement is that it must be probative 
of the level of skill of the routineer in the art as 
of the time the applicant filed his application. See In 
re Gunn, 537 F.2d 1123, 1128, 190 USPQ 402, 406 
(CCPA 1976). In that case, each of the affiants stated 
what was known at the time he executed the affidavit, 
and not what was known at the time the applicant 
filed his application.

IV.REFERENCING PRIOR ART DOCUMENTS


The commercial availability of an identified prior 
art computer system is very pertinent to the issue of 
enablement. But in some cases, this approach may not 
be sufficient to meet the applicant’s burden. Merely 
citing extracts from technical publications in an affidavit 
in order to satisfy the enablement requirement is 
not sufficient if it is not made clear that a person 
skilled in the art would know which, or what parts, of 
the cited circuits could be used to construct the 
claimed device or how they could be interconnected 
to act in combination to produce the required results. 
See In re Forman, 463 F.2d 1125, 1129, 175 
USPQ 
12, 16 (CCPA 1972). This analysis would appear to be 
less critical where the circuits comprising applicant’s 
system are essentially standard components of an 
identified prior art computer system and a standard 
device attached thereto.

Prior art patents are often relied on by applicants to 
show the state of the art for purposes of enablement. 
However, these patents must have an issue date earlier 
than the effective filing date of the application under 
consideration. See In re Budnick, 537 F.2d 535, 538, 
190 USPQ 422, 424 (CCPA 1976). An analogous 
point was made in In re Gunn, supra, where the court 
indicated that patents issued after the filing date of the 
application under examination are not evidence of 
subject matter known to any person skilled in the art 
since their subject matter may have been known only 
to the patentees and the Patent and Trademark Office.

Merely citing prior art patents to demonstrate that 
the challenged components are old may not be sufficient 
proof since, even if each of the enumerated 
devices or labelled blocks in a block diagram disclosure 
were old, per se, this 
would not make it self-evident 
how each would be interconnected to function in 
a disclosed complex combination manner. Therefore, 
the specification in effect must set forth the integration 
of the prior art; otherwise, it is likely that undue 
experimentation, or more than routine experimentation 
would be required to implement the claimed 
invention. See In re Scarbrough, 500 F.2d 560, 565, 
182 USPQ 298, 301 (CCPA 1974). The court also 
noted that any cited patents which are used by the 
applicant to demonstrate that particular box diagram 
hardware or software components are old must be 
analyzed as to whether such patents are germane to 
the instant invention and as to whether such patents 
provide better detail of disclosure as to such components 
than an applicant’s own disclosure. Also, any 
patent or publication cited to provide evidence that a 
particular programming technique is well-known in 
the programming art does not demonstrate that one 
of 
ordinary skill in the art could make and use correspondingly 
disclosed programming techniques 
unless 
both programming techniques are of approximately 
the same degree of complexity. See In re 
Knowlton, 500 F.2d 566, 572, 183 USPQ 33, 
37 
(CCPA 1974).

V.ARGUMENTS OF COUNSEL

Arguments of counsel may be effective in establishing 
that an examiner has not properly met 
his 
or 
her burden or has otherwise erred in his or her 
position. However, it must be emphasized that arguments 
of counsel alone cannot take the place of evidence 
in the record once an examiner has advanced a 
reasonable basis for questioning the disclosure. See In 
re Budnick, 537 F.2d at 538, 190 
USPQ at 424; In re 
Schulze, 346 F.2d 600, 145 USPQ 716 (CCPA 1965); 
In re Cole, 326 F.2d 769, 140 USPQ 230 (CCPA 
1964). For example, in a case where the record consisted 
substantially of arguments and opinions of 
applicant’s attorney, the court indicated that factual 
affidavits could have provided important evidence on 
the issue of enablement. See In re Knowlton, 500 F.2d 
at 572, 183 USPQ at 37; In re Wiseman, 596 F.2d 
1019, 201 USPQ 658 (CCPA 1979).





2164.07Relationship of Enablement Requirement 
to Utility Requirement 
of 35 U.S.C. 101

The requirement of 35 U.S.C. 112, first paragraph 
as to how to use the invention is different from the 
utility requirement of 35 U.S.C. 101. The requirement 
of 35 
U.S.C. 101 is that some specific, substantial, 
and credible use be set forth for the invention. On the 
other hand, 35 U.S.C. 112, first paragraph requires an 
indication of how the use (required by 35 
U.S.C. 101) 
can be carried out, i.e., how the invention can be used. 

If an applicant has disclosed a specific and substantial 
utility for an invention and provided a credible 
basis supporting that utility, that fact alone does not 
provide a basis for concluding that the claims comply 
with all the requirements of 35 U.S.C. 112, first paragraph. 
For example, if an applicant has claimed a process 
of treating a certain disease condition with a 
certain compound and provided a credible basis for 
asserting that the compound is useful in that regard, 
but to actually practice the invention as claimed a person 
skilled in the relevant art would have to engage in 
an undue amount of experimentation, the claim may 
be defective under 35 U.S.C. 112, but not 35 U.S.C. 
101. To avoid confusion during examination, any 
rejection under 35 U.S.C. 112, first paragraph, based 
on grounds other than “lack of utility” should be 
imposed separately from any rejection imposed due to 
“lack of utility” under 35 U.S.C. 101 and 35 U.S.C. 
112, first paragraph.

I.WHEN UTILITY REQUIREMENT IS NOT 
SATISFIED

A.Not Useful or Operative

If a claim fails to meet the utility requirement of 
35 
U.S.C. 101 because it is shown to be nonuseful or 
inoperative, then it necessarily fails to meet the how-
to-use aspect of the enablement requirement of 
35 
U.S.C. 112, first paragraph. As noted in In re 
Fouche, 439 F.2d 1237, 169 USPQ 429 (CCPA 1971), 
if “compositions are in fact useless, appellant’s specification 
cannot have taught how to use them.” 439 
F.2d at 1243, 169 USPQ at 434. The examiner should 
make both rejections (i.e., a rejection under 35 
U.S.C. 
112, first paragraph and a rejection under 35 
U.S.C. 
101) where the subject matter of a claim has been 
shown to be nonuseful or inoperative.

The 35 U.S.C. 112, first paragraph, rejection should 
indicate that because the invention as claimed does 
not have utility, a person skilled in the art would not 
be able to use the invention as claimed, and as such, 
the claim is defective under 35 U.S.C. 112, first paragraph. 
A 35 U.S.C. 112, first paragraph, rejection 
should not be imposed or maintained unless an appropriate 
basis exists for imposing a rejection under 
35 
U.S.C. 101. In other words, Office personnel 
should not impose a 35 U.S.C. 112, first paragraph, 
rejection grounded on a “lack of utility” basis unless a 
35 U.S.C. 101 rejection is proper. In particular, the 
factual showing needed to impose a rejection under 
35 U.S.C. 101 must be provided if a 35 U.S.C. 112, 
first paragraph, rejection is to be imposed on “lack of 
utility” grounds. See MPEP §
2107 - § 2107.03 for a 
more detailed discussion of the utility requirements of 
35 U.S.C. 101 and 112, first paragraph.

B.Burden on the Examiner

When the examiner concludes that an application is 
describing an invention that is nonuseful, inoperative, 
or contradicts known scientific principles, the burden 
is on the examiner to provide a reasonable basis to 
support this conclusion. Rejections based on 
35 
U.S.C. 112, first paragraph and 35 U.S.C. 101should be made. 

Examiner Has Initial Burden To Show That One of 
Ordinary Skill in the Art Would Reasonably 
Doubt the Asserted Utility

The examiner has the initial burden of challenging 
an asserted utility. Only after the examiner has provided 
evidence showing that one of ordinary skill in 
the art would reasonably doubt the asserted utility 
does the burden shift to the applicant to provide rebuttal 
evidence sufficient to convince one of ordinary 
skill in the art of the invention’s asserted utility. In re 
Swartz, 232 F.3d 862, 863, 56 USPQ2d 1703, 1704 
(Fed. Cir. 2000); In re Brana, 51 F.3d 1560, 1566, 34 
USPQ2d 1436, 1441 (Fed. Cir. 1995) (citing In reBundy, 642 F.2d 430, 433, 209 USPQ 48, 51 (CCPA 
1981)).





C.Rebuttal by Applicant

If a rejection under 35 U.S.C. 101 has been properly 
imposed, along with a corresponding rejection 
under 35 
U.S.C. 112, first paragraph, the burden shifts 
to the applicant to rebut the prima facie showing. In re 
Oetiker, 977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444 
(Fed. Cir. 1992). There is no predetermined amount or 
character of evidence that must be provided by an 
applicant to support an asserted utility. Rather, the 
character and amount of evidence needed to support 
an asserted utility will vary depending on what is 
claimed (Ex parte Ferguson, 117 USPQ 229, 231 (Bd. 
App. 1957)), and whether the asserted utility appears 
to contravene established scientific principles and 
beliefs. In re Gazave, 379 F.2d 973, 978, 154 USPQ 
92, 96 (CCPA 1967); In re Chilowsky, 229 F.2d 457, 
462, 108 USPQ 321, 325 (CCPA 1956). Furthermore, 
the applicant does not have to provide evidence sufficient 
to establish that an asserted utility is true 
“beyond a reasonable doubt.” In re Irons, 340 F.2d 
974, 978, 144 USPQ 351, 354 (CCPA 1965). Instead, 
evidence will be sufficient if, considered as a whole, it 
leads a person of ordinary skill in the art to conclude 
that the asserted utility is more likely than not true. 
See MPEP § 2107.02 for a more detailed discussion 
of consideration of a reply to a prima facie rejection 
for lack of utility and evaluation of evidence related to 
utility. 

II.WHEN UTILITY REQUIREMENT IS SATISFIED


In some instances, the use will be provided, but the 
skilled artisan will not know how to effect that use. In 
such a case, no rejection will be made under 35 
U.S.C. 101, but a rejection will be made under 35 
U.S.C. 112, first paragraph. As pointed out in Mowryv. Whitney, 81 U.S. (14 Wall.) 620 (1871), an invention 
may in fact have great utility, i.e., may be “a 
highly useful invention,” but the specification may 
still fail to “enable any person skilled in the art or science” 
to use the invention. 81 U.S. (14 Wall.) at 644. 

2164.08Enablement Commensurate inScope With the Claims [R-2]

All questions of enablement are evaluated against 
the claimed subject matter. The focus of the examination 
inquiry is whether everything within the scope of 
the claim is enabled. Accordingly, the first analytical 
step requires that the examiner determine exactly 
what subject matter is encompassed by the claims. 
See, e.g., AK Steel Corp. v. Sollac, 344 F.3d 1234, 
1244, 68 USPQ2d 1280, 1287 (Fed. Cir. 2003)(When 
a range is claimed, there must be reasonable enablement 
of the scope of the range. Here, the claims at 
issue encompassed amounts of silicon as high as 10% 
by weight, however the specification included statements 
clearly and strongly warning that a silicon content 
above 0.5% by weight in an aluminum coating 
causes coating problems. Such statements indicate 
that higher amounts will not work in the claimed 
invention.). The examiner should determine what 
each claim recites and what the subject matter is when 
the claim is considered as a whole, not when its parts 
are analyzed individually. No claim should be overlooked. 
With respect to dependent claims, 35 U.S.C. 
112, fourth paragraph, should be followed. This paragraph 
states that “a claim in a dependent form shall be 
construed to incorporate by reference all the limitations 
of the claim to which it refers” and requires the 
dependent claim to further limit the subject matter 
claimed. 

The Federal Circuit has repeatedly held that “the 
specification must teach those skilled in the art how to 
make and use the full scope of the claimed invention 
without ‘undue experimentation’.” In re Wright, 
999 
F.2d 1557, 1561, 27 USPQ2d 1510, 1513 (Fed. 
Cir. 1993). Nevertheless, not everything necessary to 
practice the invention need be disclosed. In fact, what 
is well-known is best omitted. In re Buchner, 929 F.2d 
660, 661, 18 USPQ2d 1331, 1332 (Fed. Cir. 1991). 
All that is necessary is that one skilled in the art be 
able to practice the claimed invention, given the level 
of knowledge and skill in the art. Further the scope of 
enablement must only bear a “reasonable correlation” 
to the scope of the claims. See, e.g., In re Fisher, 
427 
F.2d 833, 839, 166 USPQ 18, 24 (CCPA 1970).

As concerns the breadth of a claim relevant to 
enablement, the only relevant concern should be 
whether the scope of enablement provided to one 
skilled in the art by the disclosure is commensurate 
with the scope of protection sought by the claims. 
AK Steel Corp. v. Sollac, 344 F.3d 1234, 1244, 68 
USPQ2d 1280, 1287 (Fed. Cir. 2003); In re Moore, 
439 F.2d 1232, 1236, 169 USPQ 236, 239 
(CCPA 
1971). See also Plant Genetic Sys., N.V. v. DeKalb 





Genetics Corp., 315 F.3d 1335, 1339, 65 USPQ2d 
1452, 1455 (Fed. Cir. 2003) (alleged “pioneer status” 
of invention irrelevant to enablement determination).

The determination of the propriety of a rejection 
based upon the scope of a claim relative to the scope 
of the enablement involves two stages of inquiry. The 
first is to determine how broad the claim is with 
respect to the disclosure. The entire claim must be 
considered. The second inquiry is to determine if one 
skilled in the art is enabled to make and use the entire 
scope of the claimed invention without undue experimentation.


How a teaching is set forth, by specific example or 
broad terminology, is not important. In re Marzocchi, 
439 F.2d 220, 223-24 169 USPQ 367, 370 (CCPA 
1971). A rejection of a claim under 35 U.S.C. 112 as 
broader than the enabling disclosure is a first paragraph 
enablement rejection and not a second paragraph 
definiteness rejection. Claims are not rejected 
as broader than the enabling disclosure under 
35 
U.S.C. 112 for noninclusion of limitations dealing 
with factors which must be presumed to be within the 
level of ordinary skill in the art; the claims need not 
recite such factors where one of ordinary skill in the 
art to whom the specification and claims are directed 
would consider them obvious. In re Skrivan, 427 F.2d 
801, 806, 166 USPQ 85, 88 (CCPA 1970). One does 
not look to the claims but to the specification to find 
out how to practice the claimed invention. W.L. Gore 
& Assoc., Inc. v. Garlock, Inc., 721 F.2d 1540, 1558, 
220 USPQ 303, 316-17 (Fed. Cir. 1983); In re 
Johnson, 558 F.2d 1008, 1017, 194 USPQ 187, 195 
(CCPA 1977). In In re Goffe, 542 F.2d 564, 567, 
191 
USPQ 429, 431 (CCPA 1976), the court stated:

[T]o provide effective incentives, claims must adequately 
protect inventors. To demand that the first to disclose shall 
limit his claims to what he has found will work or to materials 
which meet the guidelines specified for “preferred” 
materials in a process such as the one herein involved 
would not serve the constitutional purpose of promoting 
progress in the useful arts.

When analyzing the enabled scope of a claim, the 
teachings of the specification must not be ignored 
because claims are to be given their broadest reasonable 
interpretation that is consistent with the specification. 
“That claims are interpreted in light of the 
specification does not mean that everything in the 
specification must be read into the claims.” Raytheon 
Co. v. Roper Corp., 724 F.2d 951, 957, 220 USPQ 
592, 597 (Fed. Cir. 1983), cert. denied, 469 U.S. 835 
(1984). 

The record must be clear so that the public will 
have notice as to the patentee’s scope of protection 
when the patent issues. If a reasonable interpretation 
of the claim is broader than the description in the 
specification, it is necessary for the examiner to make 
sure the full scope of the claim is enabled. Limitations 
and examples in the specification do not generally 
limit what is covered by the claims.

The breadth of the claims was a factor considered 
in Amgen v. Chugai Pharmaceutical Co., 927 F.2d 
1200, 18 USPQ2d 1016 (Fed. Cir.), cert. denied, 
502 
U.S. 856 (1991). In the Amgen case, the patent 
claims were directed to a purified DNA sequence 
encoding polypeptides which are analogs of erythropoietin 
(EPO). The Court stated that:

Amgen has not enabled preparation of DNA sequences 
sufficient to support its all-encompassing claims. . . . 
[D]espite extensive statements in the specification concerning 
all the analogs of the EPO gene that can be made, 
there is little enabling disclosure of particular analogs and 
how to make them. Details for preparing only a few EPO 
analog genes are disclosed. . . . This disclosure might well 
justify a generic claim encompassing these and similar 
analogs, but it represents inadequate support for Amgen’s 
desire to claim all EPO gene analogs. There may be many 
other genetic sequences that code for EPO-type products. 
Amgen has told how to make and use only a few of them 
and is therefore not entitled to claim all of them.

 927 F.2d at 1213-14, 18 USPQ2d at 1027. However, 
when claims are directed to any purified and isolated 
DNA sequence encoding a specifically named 
protein where the protein has a specifically identified 
sequence, a rejection of the claims as broader than the 
enabling disclosure is generally not appropriate 
because one skilled in the art could readily determine 
any one of the claimed embodiments. 

See also In re Wright, 999 F.2d 1557, 1562, 
27 
USPQ2d 1510, 1513 (Fed. Cir. 1993) (The evidence 
did not show that a skilled artisan would have 
been able to carry out the steps required to practice 
the full scope of claims which encompass “any and alllive, non-pathogenic vaccines, and processes for making 
such vaccines, which elicit immunoprotective 
activity in any animal toward any RNA virus.” (original 
emphasis)); In re Goodman, 11 F.3d 1046, 
1052,
29 USPQ2d 2010, 2015 (Fed. Cir. 1993) (The 





specification did not enable the broad scope of the 
claims for producing mammalian peptides in plant 
cells because the specification contained only an 
example of producing gamma-interferon in a dicot 
species, and there was evidence that extensive experimentation 
would have been required for encoding 
mammalian peptide into a monocot plant at the time 
of filing); In re Fisher, 427 F.2d 833, 839, 166 USPQ 
18, 24 (CCPA 1970) (Where applicant claimed a composition 
suitable for the treatment of arthritis having a 
potency of “at least” a particular value, the court held 
that the claim was not commensurate in scope with 
the enabling disclosure because the disclosure was not 
enabling for compositions having a slightly higher 
potency. Simply because applicant was the first to 
achieve a composition beyond a particular threshold 
potency did not justify or support a claim that would 
dominate every composition that exceeded that 
threshold value.); In re Vaeck, 947 F.2d 488, 495, 
20 
USPQ2d 1438, 1444 (Fed. Cir. 1991) (Given the 
relatively incomplete understanding in the biotechnological 
field involved, and the lack of a reasonable 
correlation between the narrow disclosure in the specification 
and the broad scope of protection sought in 
the claims, a rejection under 35 U.S.C. 112, first paragraph 
for lack of enablement was appropriate.).

If a rejection is made based on the view that the 
enablement is not commensurate in scope with the 
claim, the examiner should identify the subject matter 
that is considered to be enabled.

2164.08(a)Single Means Claim

A single means claim, i.e., where a means recitation 
does not appear in combination with another recited 
element of means, is subject to an undue breadth 
rejection under 35 U.S.C. 112, first paragraph. In re 
Hyatt, 708 F.2d 712, 714-715, 218 USPQ 195, 197 
(Fed. Cir. 1983) (A single means claim which covered 
every conceivable means for achieving the stated purpose 
was held nonenabling for the scope of the claim 
because the specification disclosed at most only those 
means known to the inventor.). When claims depend 
on a recited property, a fact situation comparable to 
Hyatt is possible, where the claim covers every conceivable 
structure (means) for achieving the stated 
property (result) while the specification discloses at 
most only those known to the inventor. 

2164.08(b)Inoperative Subject Matter

The presence of inoperative embodiments within 
the scope of a claim does not necessarily render a 
claim nonenabled. The standard is whether a skilled 
person could determine which embodiments that were 
conceived, but not yet made, would be inoperative or 
operative with expenditure of no more effort than is 
normally required in the art. Atlas Powder Co. v. E.I. 
du Pont de Nemours & Co., 750 F.2d 1569, 1577, 
224 
USPQ 409, 414 (Fed. Cir. 1984) (prophetic 
examples do not make the disclosure nonenabling).

Although, typically, inoperative embodiments are 
excluded by language in a claim (e.g., preamble), the 
scope of the claim may still not be enabled where 
undue experimentation is involved in determining 
those embodiments that are operable. A disclosure of 
a large number of operable embodiments and the 
identification of a single inoperative embodiment did 
not render a claim broader than the enabled scope 
because undue experimentation was not involved in 
determining those embodiments that were operable. 
In re Angstadt, 537 F.2d 498, 502-503, 190 USPQ 
214, 218 (CCPA 1976). However, claims reading on 
significant numbers of inoperative embodiments 
would render claims nonenabled when the specification 
does not clearly identify the operative embodiments 
and undue experimentation is involved in 
determining those that are operative. Atlas Powder 
Co. v. E.I. duPont de Nemours & Co., 750 F.2d 1569, 
1577, 224 USPQ 409, 414 (Fed. Cir. 1984); In reCook, 439 F.2d 730, 735, 169 USPQ 298, 302 (CCPA 
1971).

2164.08(c)Critical Feature Not Claimed 

A feature which is taught as critical in a specification 
and is not recited in the claims should result in a 
rejection of such claim under the enablement provision 
section of 35 U.S.C. 112. See In re Mayhew, 
527 
F.2d 1229, 1233, 188 USPQ 356, 358 
(CCPA 
1976). In determining whether an unclaimed 
feature is 
critical, the entire disclosure must be considered. 
Features which are merely preferred are not 
to be considered critical. In re Goffe, 542 F.2d 564, 
567, 191 
USPQ 429, 431 (CCPA 1976). 

Limiting an applicant to the preferred materials in 
the absence of limiting prior art would not serve the 
constitutional purpose of promoting the progress in 
the useful arts. Therefore, an enablement rejection 
based on the grounds that a disclosed critical limitation 
is missing from a claim should be made only 
when the language of the specification makes it clear 
that the limitation is critical for the invention to function 
as intended. Broad language in the disclosure, 
including the abstract, omitting an allegedly critical 
feature, tends to rebut the argument of criticality.