2138.05 “Reduction to Practice”
This MPEP section has limited applicability to applications subject to examination under the first inventor to file (FITF) provisions of the AIA.
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Reduction to practice may be an actual reduction or a constructive reduction to practice which occurs when a patent application on the claimed invention is filed.
- The filing of a patent application serves as conception and constructive reduction to practice of the subject matter described in the application.
- Thus the inventor need not provide evidence of either conception or actual reduction to practice when relying on the content of the patent application.
A reduction to practice can be done by another on behalf of the inventor.
I. CONSTRUCTIVE REDUCTION TO PRACTICE REQUIRES COMPLIANCE WITH 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, FIRST PARAGRAPH
When a party to an interference seeks the benefit of an earlier-filed U.S. patent application, the earlier application must meet the requirements of 35 U.S.C. 120 and 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph for the subject matter of the count.
- The earlier application must meet the enablement requirement and must contain a written description of the subject matter of the interference count.
Proof of a constructive reduction to practice requires sufficient disclosure under the “how to use” and “how to make” requirements of 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph.
A constructive reduction to practice is not proven unless the specification discloses a practical utility where one would not be obvious. Prior art which disclosed an anticonvulsant compound which differed from the claimed compound only in the absence of a -CH2- group connecting two functional groups was not sufficient to establish utility of the claimed compound because the compounds were not so closely related that they could be presumed to have the same utility.
The purpose of the written description requirement is “to ensure that the inventor had possession, as of the filing date of the application relied on, of the specific subject matter later claimed by him.”
The written description must include all of the limitations of the interference count, or the applicant must show that any absent text is necessarily comprehended in the description provided and would have been so understood at the time the patent application was filed.
- Furthermore, the written description must be sufficient, when the entire specification is considered, such that the “necessary and only reasonable construction” that would be given it by a person skilled in the art is one that clearly supports each positive limitation in the count.
II. REQUIREMENTS TO ESTABLISH ACTUAL REDUCTION TO PRACTICE
“In an interference proceeding, a party seeking to establish an actual reduction to practice must satisfy a two-prong test:
- the party constructed an embodiment or performed a process that met every element of the interference count, and
- the embodiment or process operated for its intended purpose.
The same evidence sufficient for a constructive reduction to practice may be insufficient to establish an actual reduction to practice, which requires a showing of the invention in a physical or tangible form that shows every element of the count.
- For an actual reduction to practice, the invention must have been sufficiently tested to demonstrate that it will work for its intended purpose, but it need not be in a commercially satisfactory stage of development.
- If a device is so simple, and its purpose and efficacy so obvious, construction alone is sufficient to demonstrate workability.
III. TESTING REQUIRED TO ESTABLISH AN ACTUAL REDUCTION TO PRACTICE
“The nature of testing which is required to establish a reduction to practice depends on the particular facts of each case, especially the nature of the invention.”
IV. REDUCTION TO PRACTICE REQUIRES RECOGNITION AND APPRECIATION OF THE INVENTION
The invention must be recognized and appreciated for a reduction to practice to occur.
The rule that conception and reduction to practice cannot be established nunc pro tunc simply requires that in order for an experiment to constitute an actual reduction to practice, there must have been contemporaneous appreciation of the invention at issue by the inventor….
- Subsequent testing or later recognition may not be used to show that a party had contemporaneous appreciation of the invention.
- However, evidence of subsequent testing may be admitted for the purpose of showing that an embodiment was produced and that it met the limitations of the count.
V. RECOGNITION OF THE INVENTION BY ANOTHER MAY INURE TO THE BENEFIT OF THE INVENTOR
“Inurement involves a claim by an inventor that, as a matter of law, the acts of another person should accrue to the benefit of the inventor.”
Before a non-inventor’s recognition of the utility of the invention can inure to the benefit of the inventor, the following three-prong test must be met:
- the inventor must have conceived of the invention,
- the inventor must have had an expectation that the embodiment tested would work for the intended purpose of the invention, and
- the inventor must have submitted the embodiment for testing for the intended purpose of the invention.
The device reduced to practice must include every limitation of the count.
- Every limitation in a count is material and must be proved to establish an actual reduction to practice.
VII. CLAIMED INVENTION IS NOT ACTUALLY REDUCED TO PRACTICE UNLESS THERE IS A KNOWN UTILITY
Utility for the invention must be known at the time of the reduction to practice.
VIII. A PROBABLE UTILITY MAY NOT BE SUFFICIENT TO ESTABLISH UTILITY
A probable utility does not establish a practical utility, which is established by actual testing or where the utility can be “foretold with certainty.”
