How is compliance with the best mode requirement determined?

Determining compliance with the best mode requirement involves a two-prong inquiry, as outlined in MPEP 2165:

1. Subjective Inquiry: Determine if the inventor possessed a best mode for practicing the invention at the time of filing. This focuses on the inventor’s state of mind.
2. Objective Inquiry: If a best mode existed, determine if the written description adequately disclosed it for a person skilled in the art to practice. This focuses on the scope of the claimed invention and the level of skill in the art.

The MPEP cites Eli Lilly & Co. v. Barr Labs. Inc. to support this two-prong approach:

“Determining compliance with the best mode requirement requires a two-prong inquiry. First, it must be determined whether, at the time the application was filed, the inventor possessed a best mode for practicing the invention. This is a subjective inquiry which focuses on the inventor’s state of mind at the time of filing. Second, if the inventor did possess a best mode, it must be determined whether the written description disclosed the best mode such that a person skilled in the art could practice it.“

To learn more:

• best mode compliance
• patent examination
• inventor’s state of mind
• written description