A patentee brought an action for infringement of patents relating to cell culturing. The claims of the patent required that the cell culture medium be conditioned by “culturing . . . cells in three dimensions.”  The district court construed that phrase to exclude cells grown on microcarrier beads. Because the accused process used beads, the district court granted summary judgment of noninfringement.

The Federal Circuit affirmed. The court acknowledged that the use of beads fell within the ordinary meaning of the phrase “culturing . . . cells in three dimensions.” But it held that the patentee had redefined that phrase to exclude the use of beads. In reaching this conclusion, the court relied on several references to “beads” in the intrinsic record, which amounted to “an implicit disclaimer of culturing with beads . . so clear that it equates to an explicit one.”  The patentee used the disjunctive “or” and “as opposed to” to distinguish bead cultures from three-dimensional cultures. And by using the term “i.e.,” the patentee had redefined culturing in beads as a two-dimensional culturing method. Finally, during prosecution, the patentees had distinguished between two- and three-dimensional cultures as having distinct and different results.

The majority gave no weight to expert testimony that culturing with beads in three dimensions produces the same benefits as other culturing in three dimensions. This portion of the expert’s testimony “consist[ed] exclusively of three conclusory affirmations elicited by leading questions,” and was lacking in “any convincing detail.”

Judge Rader dissented. He argued that the intrinsic references relied on by the majority were ambiguous. Specifically, he contended that because cells can be cultured on beads in two or three dimensions, the references referred to beads in the particular context of two dimensions. In reaching this conclusion, Judge Rader relied on the same expert testimony that the majority had dismissed. In Judge Rader’s view, however, the expert’s testimony was unrefuted and, when viewed as a whole, was entitled to “great weight and respect.” The leading nature of the questions was nothing more than a waivable defect, and the accused infringer had not objected.

A copy of the opinion can be found here.