While not every preference constitutes a best mode for purposes of § 112, the preferred embodiment of the invention must be disclosed.

Ajinomoto Co., Inc. v. Int’l Trade Comm’n, No. 2009-1081 (Fed. Cir. Mar. 8, 2010).

The two patents at issue relate to improved methods of producing L-lysine through the cultivation of E. coli bacteria “that have been genetically engineered to produce and accumulate greater quantities of lysine than naturally occurring (or wild-type) bacterial strains.” The ITC found the asserted claims invalid for failure to comply with the best mode requirement of 35 U.S.C. § 112 and also that one of the patents was unenforceable due to inequitable conduct. On appeal, the Federal Circuit affirmed.

The Federal Circuit held that “[t]o satisfy the best mode requirement, an inventor must disclose the preferred embodiment of his invention as well as preferences that materially affect the properties of the invention.” However, “[t]he disclosure requirement…is limited to ‘the invention defined by the claims’ [and] [s]ubject matter outside the scope of the claims falls outside of the best mode requirement.” The patentee argued that the ITC misconstrued the scope of its claimed inventions and the scope of the best mode requirement. Specifically, the patentee contended that the ITC incorrectly expanded the scope of the best mode requirement beyond the patents’ “innovative aspects” to include unrelated and non-novel subject matter, such as the creation and use of unclaimed host strains.

The Federal Circuit held that the claims covered more than the specific mutations as defined by the patentee, and included the cultivation of a bacterial host strain containing those mutations. “[W]ithin the scope of the best mode requirement [is] an obligation to disclose the inventors’ preferred host strains.” In this case, the patentee did not disclose the preferred host strains as of the filing date.

The patentee waived its right to appeal the issue of inequitable conduct because it provided only a “conclusory assertion unaccompanied by developed argumentation” on the issue.

A copy of the opinion can be found here.