What is a Markush group in patent claims?

A Markush group is a claim construction that lists alternatives to define a limitation in a patent claim. As stated in the MPEP 2173.05(h): “Claims that set forth a list of alternatives from which a selection is to be made are typically referred to as Markush claims, after the appellant in Ex parte Markush, 1925…

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Is it acceptable to use ‘optionally’ in patent claims?

Yes, using the term ‘optionally’ in patent claims can be acceptable, but it requires careful consideration. The MPEP 2173.05(h) provides guidance on this: “In Ex parte Cordova, 10 USPQ2d 1949 (Bd. Pat. App. & Inter. 1989) the language ‘containing A, B, and optionally C’ was considered acceptable alternative language because there was no ambiguity as…

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What is a proper Markush group in patent claims?

What is a proper Markush group in patent claims? A proper Markush group in patent claims is a closed group of alternatives. According to MPEP 2117, “A Markush claim contains an ‘improper Markush grouping’ if either: (1) the members of the Markush group do not share a ‘single structural similarity’ or (2) the members do…

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How does the MPEP address negative limitations in patent claims?

The MPEP addresses negative limitations in patent claims in MPEP 2173.05(i), which is closely related to the discussion on alternative limitations in MPEP 2173.05(h). The MPEP states: “The current view of the courts is that there is nothing inherently ambiguous or uncertain about a negative limitation.” This guidance indicates that negative limitations are generally acceptable…

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How does the MPEP address the use of “consisting of” vs. “comprising” in alternative limitations?

The MPEP addresses the use of “consisting of” vs. “comprising” in alternative limitations in MPEP 2173.05(h). The distinction is crucial for the definiteness and scope of the claim: “A Markush grouping is a closed group of alternatives, i.e., the selection is made from a group ‘consisting of’ (rather than ‘comprising’ or ‘including’) the alternative members.”…

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What is a Markush group in a patent claim?

A Markush group is a way of claiming a list of alternatively useable members in a patent claim. According to MPEP 2173.05(h): “A Markush grouping is a closed group of alternatives, i.e., the selection is made from a group ‘consisting of’ (rather than ‘comprising’ or ‘including’) the alternative members.” Markush groups are typically used to…

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What are the key considerations for “lists of alternatives” in patent claims?

When dealing with lists of alternatives in patent claims, there are several key considerations outlined in MPEP 2173.05(h): Proper Markush format: The MPEP states, “A Markush grouping is a closed group of alternatives, i.e., the selection is made from a group ‘consisting of’ (rather than ‘comprising’ or ‘including’) the alternative members.” Indefiniteness: The MPEP warns,…

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