When can claims with inoperative embodiments be considered nonenabled?

Claims with inoperative embodiments can be considered nonenabled when they include significant numbers of inoperative embodiments and undue experimentation is required to determine which are operative. The MPEP 2164.08(b) states:

“However, claims reading on significant numbers of inoperative embodiments would render claims nonenabled when the specification does not clearly identify the operative embodiments and undue experimentation is involved in determining those that are operative.”

This guidance is based on case law, including Atlas Powder Co. v. E.I. duPont de Nemours & Co. and In re Cook. The key factors are the number of inoperative embodiments, the clarity of the specification in identifying operative embodiments, and the level of experimentation required to distinguish between operative and inoperative embodiments.

To learn more:

• Nonenabled claims
• Inoperative embodiments
• Undue experimentation
• Patent specification