MPEP 2173.05(q)
"Use" Claims

Ninth Edition of the MPEP, Revision 07.2022, Last Revised in February 2023

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2173.05(q)    "Use" Claims [R-10.2019]

Attempts to claim a process without setting forth any steps involved in the process generally raises an issue of indefiniteness under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. For example, a claim which read: "[a] process for using monoclonal antibodies of claim 4 to isolate and purify human fibroblast interferon" was held to be indefinite because it merely recites a use without any active, positive steps delimiting how this use is actually practiced. Ex parte Erlich, 3 USPQ2d 1011 (Bd. Pat. App. & Inter. 1986).

"Use" claims that do not purport to claim a process, machine, manufacture, or composition of matter fail to comply with 35 U.S.C. 101. In re Moreton, 288 F.2d 708, 709, 129 USPQ 227, 228 (CCPA 1961)("one cannot claim a new use per se, because it is not among the categories of patentable inventions specified in 35 U.S.C. § 101 "). In Ex parte Dunki, 153 USPQ 678 (Bd. App. 1967), the Board held the following claim to be an improper definition of a process: "The use of a high carbon austenitic iron alloy having a proportion of free carbon as a vehicle brake part subject to stress by sliding friction." In Clinical Products Ltd. v. Brenner, 255 F. Supp. 131, 149 USPQ 475 (D.D.C. 1966), the district court held the following claim was definite, but that it was not a proper process claim under 35 U.S.C. 101: "The use of a sustained release therapeutic agent in the body of ephedrine absorbed upon polystyrene sulfonic acid."

Although a claim should be interpreted in light of the specification disclosure, it is generally considered improper to read limitations contained in the specification into the claims. See In re Prater, 415 F.2d 1393, 162 USPQ 541 (CCPA 1969) and In re Winkhaus, 527 F.2d 637, 188 USPQ 129 (CCPA 1975), which discuss the premise that one cannot rely on the specification to impart limitations to the claim that are not recited in the claim.


It is appropriate to reject a claim that recites a use but fails to recite steps under 35 U.S.C. 101 and 35 U.S.C. 112(b) if the facts support both rejections. For failure to recite a claim within one of the statutory classes under 35 U.S.C. 101, the appropriate form paragraph is 7.05.01. For indefiniteness under 35 U.S.C. 112(b), the appropriate form paragraph is 7.34.01.


It is often difficult to draw a fine line between what is permissible, and what is objectionable from the perspective of whether a claim is definite. In the case of Ex parte Porter, 25 USPQ2d 1144 (Bd. Pat. App. & Inter. 1992), the Board held that a claim which clearly recited the step of "utilizing" was not indefinite under 35 U.S.C. 112, second paragraph. (Claim was to "A method for unloading nonpacked, nonbridging and packed, bridging flowable particle catalyst and bead material from the opened end of a reactor tube which comprises utilizing the nozzle of claim 7.").