What is a proper Markush grouping?
A proper Markush grouping, as defined in MPEP 803.02, must meet two criteria:
- The members of the Markush group share a “single structural similarity”
- The members share a common use
The MPEP cites the Supplementary Guidelines, which state: “Where a Markush grouping describes part of a combination or process, the members following ‘selected from the group consisting of’ (or a similar introductory phrase) must be substitutable, one for the other, with the expectation that the same intended result would be achieved.”
It’s important to note that for chemical compounds, the propriety of the grouping is determined by considering the compound as a whole, not by breaking it down into elements or components.
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