What defines a Markush Group in patent claims?

A Markush Group in patent claims refers to a claim structure that illustrates a variable group defined by alternative elements, allowing for different substitutions within the group. This structure permits the listing of multiple components, typically in a way that emphasizes alternatives rather than absolute selections. The use of the term "comprising" is common in this context, but the essence of a Markush Group lies in its flexibility to allow different members to be included without limiting the scope of the claim to a single embodiment.

The significance of a Markush Group is that it facilitates broader protection for the invention by encompassing a class of compounds or materials, which may provide varying functionalities or properties while still falling under the same inventive concept. This means that the claim can cover multiple substances that share a common feature, thus enhancing the patent's robustness against infringement.

The other answer choices do not precisely capture the fundamental concept of a Markush Group. While they may reference certain aspects of claims, they do not illustrate the specific purpose and structure that defines a Markush Group in the context of patent claims.