What is the key consideration when analyzing obviousness of species claims?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

The key consideration is whether the claimed species or subgenus would have been obvious to one of ordinary skill in the pertinent art at the relevant time. As stated in MPEP 2144.08:

“The patentability of a claim to a specific compound, species, or subgenus embraced by a prior art genus should be analyzed no differently than any other claim for purposes of 35 U.S.C. 103. ‘The section 103 requirement of unobviousness is no different in chemical cases than with respect to other categories of patentable inventions.’”

This means examiners should evaluate the totality of the circumstances and evidence when determining obviousness, rather than relying on per se rules.