Markush Claiming in Chemical Patents

When a Markush group is used for claiming a chemical invention, the members of the group either need to belong to a common or recognized class or share at least one 

20MPEP2111.03 quoting In re Herz, 537 F.2d 549, 551-552 (CCPA 1976), emphasis in the original. 

22Of course, the elements of the claims themselves are die primary way of controlling die scope of the claim, and the transition phrases can be seen as setting die limits on the inclusiveness or exclusiveness of claim beyond the explicitly cited elements. 

23MPEP 803.02 quoting from Ex Parte Markush, 1925 C.D. 126 (Comm r Pat. 1925). 

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Before diving into claim interpretation, let s first review some basic aspects of claims, such as the types of claims, the structure of claims, universal claim transitions, and finally, Markush claiming in chemical patents. 

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