What role does undue experimentation play in determining enablement for claims with inoperative embodiments?

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.

Undue experimentation plays a crucial role in determining enablement for claims with inoperative embodiments. According to MPEP 2164.08(b):

“[T]he scope of the claim may still not be enabled where undue experimentation is involved in determining those embodiments that are operable.”

The key consideration is whether a skilled person can identify operative embodiments without expending more effort than is normally required in the art. If significant experimentation is needed to distinguish between operative and inoperative embodiments, the claim may be considered nonenabled, especially when there are a large number of inoperative embodiments within the claim scope.