Claims are not indefinite if the intrinsic evidence provides a general guideline and examples sufficient to enable a person of ordinary skill in the art to determine the scope of the claims, even if some experimentation is required.
The patents-in-suit were directed toward various techniques for labeling and detecting nucleic acids. The district court granted summary judgment in favor of the accused infringer. As to three of the patents, the district court held that the “not interfering substantially” language in the asserted claims was indefinite and, alternatively, found that those patents were anticipated by the prior art.
As a preliminary matter, the Federal Circuit noted that a claim cannot be both indefinite and anticipated. Anticipation involves a two-step analysis. First, the claim must be construed. Second, the properly construed claim must be compared to the prior art. An indefinite claim, by definition, cannot be construed, and “[w]ithout a discernable claim construction, an anticipation analysis cannot be performed.”
The Federal Circuit held that the “not interfering substantially” language, despite lacking reference to a precise numerical measurement, was not indefinite. In context, the word “substantially” denoted language of magnitude because it described how much interference could occur during hybridization (i.e., an insubstantial amount). The language of the claims provided at least some guidance as to how much interference would be tolerated. The specification also provided additional examples of suitable linkage groups and some criteria for selecting them. Moreover, the prosecution history revealed that the patentee overcame an indefiniteness rejection before the PTO by submitting a declaration under 37 C.F.R. § 1.132, which listed eight specific linkage groups that the patentee declared did not substantially interfere with hybridization or detection. Accordingly, the intrinsic evidence provided a general guideline and examples sufficient to enable a person of ordinary skill in the art to determine the scope of the claims.
In contrast to the subjectivity that led to a finding of indefiniteness in Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342 (Fed. Cir. 2005), the binding strength of a DNA strand in this case depended on the length and sequence of the strand, and not on the subjective opinion of the particular chemist performing the hybridization. In addition, claims are not indefinite even if some experimentation is required to determine their exact scope.
A copy of the opinion can be found here.