A Markush group is a claim drafting tool used to capture various alternative elements or species in a single claim. A typical Markush group is structured using the following language:
“selected from the group consisting of A, B, and C” or “selected from the group consisting essentially of A, B, and C.
To properly be considered a Markush group, the associated elements (e.g., A, B, and C, in the above example) must share a structural similarity and common use.
Markush groupings have a strong presumption of being read as a “closed” group such that other elements are not “read into” the claim. In a limited number of instances, this presumption may be overcome.
These groups are routinely associated with the metallurgy, chemical, pharmaceutical, medical, and biotech fields; however, this drafting tool may be used in connection with any technical field.