¶ 8.40 Improper Markush Grouping Rejection 
Claim [1] rejected on the basis that it contains an improper Markush grouping of alternatives. See In re Harnisch, 631 F.2d 716, 721-22 (CCPA 1980) and Ex parte Hozumi, 3 USPQ2d 1059, 1060 (Bd. Pat. App. & Int. 1984). A Markush grouping is proper if the alternatives defined by the Markush group (i.e., alternatives from which a selection is to be made in the context of a combination or process, or alternative chemical compounds as a whole) share a "single structural similarity" and a common use. A Markush grouping meets these requirements in two situations. First, a Markush grouping is proper if the alternatives are all members of the same recognized physical or chemical class or the same art-recognized class, and are disclosed in the specification or known in the art to be functionally equivalent and have a common use. Second, where a Markush grouping describes alternative chemical compounds, whether by words or chemical formulas, and the alternatives do not belong to a recognized class as set forth above, the members of the Markush grouping may be considered to share a "single structural similarity" and common use where the alternatives share both a substantial structural feature and a common use that flows from the substantial structural feature. See MPEP § 2117.
The Markush grouping of [2] is improper because the alternatives defined by the Markush grouping do not share both a single structural similarity and a common use for the following reasons: [3].
To overcome this rejection, Applicant may set forth each alternative (or grouping of patentably indistinct alternatives) within an improper Markush grouping in a series of independent or dependent claims and/or present convincing arguments that the group members recited in the alternative within a single claim in fact share a single structural similarity as well as a common use.
Examiner Note:
1. In bracket 1, insert claim number(s) and "is" or "are" as appropriate.
2. In bracket 2, insert a description of the Markush group(s) that are improper.
3. In bracket 3, explain why these alternatives do not meet the requirements for a proper Markush grouping, i.e., why the alternatives are not all members of the same recognized physical or chemical class or the same art-recognized class; and/or why the members are not considered to be functionally equivalent and have a common use; and/or why (if the Markush grouping describes alternative chemical compounds), the alternatives do not share both a substantial structural feature and a common use that flows from the substantial structural feature. See MPEP § 2117.
4. If an election of species requirement is appropriate, this form paragraph should only be used after applicant has made an election.