How can a Markush group be presented according to patent law?

A Markush group is a specific way to describe a class of compounds in patent claims that encompasses various alternatives. This type of group is particularly useful in chemical and pharmaceutical patents, where a generic class of compounds is claimed.

The correct presentation of a Markush group involves using phrases like "selected from" in conjunction with a description of the group being selected from. This format allows for the inclusion of a wide variety of compounds within the claim while still providing clarity and limiting the scope precisely enough to comply with patentability requirements.

When employing this method, the structure of the claim would typically be "A compound selected from the group consisting of A, B, and C," where A, B, and C represent distinct members of the group. This ensures that the claim covers a range of alternatives while maintaining a clear definition of what is included and what isn't, thereby enhancing the scope and effectiveness of the patent protection.

In contrast, just listing a singular member does not adequately provide the breadth that a Markush group should represent, and specifying a range of compounds might not conform to the necessary wording that explicitly draws from a specified selection. Visual diagrams can support the understanding of a Markush group but are not appropriate for defining it in the legal sense of patent law