The U.S. Court of Appeals for the Federal Circuit, invoking the § 112, ¶ 2 written description requirement, held that a party copying claims to provoke an interference must have written description support in its own specification to support the claims in issue. However, following its own precedent, the Court concluded that when construing such a claim for purposes of evaluating validity, the claim should be construed in light of the specification and prosecution history of the host patent or application. Agilent Technologies, Inc. v. Affymetrix, Inc., Case No. 08-1466, (Fed. Cir., June 4, 2009) (Rader, J.).

The case came to the Federal Circuit as an appeal from a district court § 146 proceeding against Affymetrix. The district court denied Agilent’s motion for summary judgment with regard to written description under § 112, thus sustaining the decision of the Board of Patent Appeals and Interferences (the Board) awarding priority to Affymetrix. Agilent appealed.

The disputed claims pertain to “microarray hybridization,” a technique for performing multiple genetic analyses on a small fluid sample. Using this technique, a tester can perform millions of genetic tests in a single small assay. The disputed invention focuses on a method of mixing a fluid sample containing the genetic material of interest for thorough contact with the surface of a microarray, typically a glass slide bearing millions of molecular probes.

Agilent’s patent discloses a method of conducting a hybridization reaction in a closed chamber where bubbles are formed by nucleation in a film of fluid. Movement of the bubbles (by application of heat) causes mixing.

Affymetrix’s application discloses three embodiments, called “agitation systems,” for mixing fluid through a cavity during hybridization. Using ports, vents and valves, an agitator injects gas into cavities in an alternating manner, thereby forcing fluid into and out of the cavity so that the targets and probes mix to effect hybridization. Bubbles agitate the fluid as it circulates through the system.

Before the Board, Agilent filed a single substantive preliminary motion challenging the validity of the copied claims on the grounds that the Affymetrix application did not describe the invention adequately under § 112, ¶ 1 to show actual possession of the bubble-mixing invention. The Board ruled that Agilent did not prove that the Affymetrix application lacked adequate written description to support the count (the interfering claims) and awarded priority to the Affymetrix application over the Agilent patent.

Agilent sought district court review under 35 U.S.C. § 146. At the district court, the parties submitted new expert reports and testimony from their respective expert witnesses. The district court held a claim construction hearing and consequently granted Affymetrix’s motion for summary judgment, thereby affirming the Board. In this appeal to the Federal Circuit, Agilent challenged the trial court’s claim construction and written description decisions.

In terms of claim construction, the Federal Circuit, citing its 1992 In re Spina decision, concluded that “[w]hen interpretation is required of a claim that is copied for interference purposes, the copied claim is viewed in the context of the patent from which it was copied.”

The Court also noted that in accordance with its 1998 decision in Rowe v. Dror (another case arising in the context of a patent interference), when considering validity, the PTO should interpret a claim in light of its host disclosure, just as it would during ex parte prosecution.

In this case, in reversing the district court, the Court reasoned that the Spina rule should be applied to the written description issue, i.e., whether the Affymetrix application contains adequate basis to copy a claim from Agilent’s patent and thereby challenge Agilent’s priority of invention. In other words, in assessing whether both parties have a right to claim the same subject matter, the claim construction analysis must be made in the context of the specification from which the claims were copied. On that basis the Court concluded that the Affymetrix application did not meet the written description requirement to support the count.

The Court noted that if the issue were whether the claim is patentable to one or the other party in light of prior art, the Rowe rule would apply and the claim would be evaluated in light of the host specification.

As the Court summarized, “when a party challenges written description support for an interference count or the copied claim in an interference, the originating disclosure provides the meaning of the pertinent claim language. When a party challenges a claim’s validity under § 102 or § 103, however, this court and the Board must interpret the claim in light of the specification in which it appears.”