When I did my Master’s thesis, I studied endocrine physiology in rats. Lots and lots of rats. Hence, I spent many a day preserving and fixing tissue samples and sitting at a microtome [1] cutting slices of tissue for mounting on slides for staining. So, I felt a real affection for the recent patent case of Ventana Medical Systems v. Biogenex Laboratories (06-1074) [2] .Ventana had appealed a judgment of noninfringement of U.S. Pat. No. 6,352,861 [3] in favor of BioGenex claiming the district court erred in its claim construction. The patent at issue relates to automated methods and apparatuses for staining microscope slides. With immunostaining, you first mount tissue samples on microscope slides then treat the slides with various reagents such as antibody stains. The stained slides are examined to detect the presence of diseases.The ’861 patent claims automated apparatuses and methods used to perform a variety of biological assays, including immunostaining and Ventana filed suit against BioGenex alleging infringement of the ’861 patent.
The district court held a Markman hearing [4] and construed certain disputed claim terms and the sole issue on appeal was the proper construction of the claim term “dispensing” in the ’861 patent. Claim 1 reads: “A method of dispensing reagents onto a slide…”
The district court construed the “dispensing” claim limitation to require “direct dispensing,” meaning that the reagent is dispensed directly from the reagent container onto the slide, rather than utilizing an intermediate transport mechanism to transfer reagent from the reagent container to the slide since the claim states that the reagent in the reagent container is dispensed onto the slide, meaning the reagent is dispensed directly from the reagent container.
After construing the term “dispensing” to mean “direct dispensing,” the district court held that the inventors disclaimed a particular type of dispensing, “sip and spit” dispensing, during the prosecution of an ancestor application. In “sip and spit” dispensing, an intermediate transport mechanism such as a pipette uses suction to “sip” the reagent from the reagent container and then releases or “spits” the reagent onto the slide.
The district court felt that the specification disclaimed the sip method in stating:
. . . Wakatake et al teaches reagent tables positioned side by side with a reaction table. (Wakatake et al, Figure 2). This side by side configuration precludes dispensing of the reagent “directly to a sample” or the incorporation of a “reagent delivery zone” as set forth in Claim 1 of the present invention. The Wakatake side by side configuration requires an additional device, a reagent pipetting device, to transfer the reagent between tables and mediate the dispensing of reagent to the sample. The reagent pipetting device is used to suck up an aliquot of reagent from a reagent container on one of at least two reagent tables, pivot so that the pipetting tube of the device is held just above a selected reaction vessel on a separate reaction table, and dispense the aliquot of reagent to the vessel (Wakatake at column 4, line 42 to column 5, line 10). Such devices are referred to in the trade as “sip and spit” devices.
On appeal, the CAFC stated that:
Claim terms “‘are generally given their ordinary and customary meaning.’” Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en banc) (quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). And “the ordinary and customary meaning of a claim term is the meaning that the term would have to a person of ordinary skill in the art.” Id. at 1313.
The CAFC then agreed with Ventana that there is nothing in the record to suggest that a person of ordinary skill in the art would interpret the disclosure and claims of the ’861 patent to mean that the term “dispensing” is limited to “direct dispensing.” Although “direct dispensing” is one type of dispensing, other types of dispensing, such as “sip and spit” dispensing, also fall within the ordinary meaning of “dispensing.”
While BioGenex argued that the patent’s specification requires a narrow construction of “dispensing,” the CAFC held that this is not a case where the inventor’s distinguishing the invention over the prior art in the specification results in a disavowal of coverage by the inventor of features in the prior art:
“It is a ‘bedrock principle’ of patent law that ‘the claims of a patent define the invention to which the patentee is entitled the right to exclude.’” Phillips, 415 F.3d at 1312 (quoting Innova/Pure Water, Inc. v. Safari Water Filtration Sys., Inc., 381 F.3d 1111, 1115 (Fed. Cir. 2004)). “[A]lthough the specification often describes very specific embodiments of the invention, we have repeatedly warned against confining the claims to those embodiments.” Id. at 1323. While the fact that the disclosed embodiments are limited can assist in interpreting claim language, the mere fact that the ’861 patent discloses embodiments in which the reagent container is also the reagent dispenser does not in and of itself mean that the method claims at issue are limited to the disclosed embodiments.
In looking at the doctrine of prosecution disclaimer, the court said:
Accordingly, we examine the patent’s prosecution history, when placed in evidence, to determine whether the inventor disclaimed a particular interpretation of a claim term during the prosecution of the patent in suit or during the prosecution of an ancestor application. Id.; Advanced Cardiovascular Sys. v. Medtronic, Inc., 265 F.3d 1294, 1305-06 (Fed. Cir. 2001). But the doctrine of prosecution disclaimer generally does not apply when the claim term in the descendant patent uses different language.
The court didn’t buy it since claims 1 and 5 of the ’861 patent use different claim language — that is, they do not require that reagent be “dispensable directly to a sample” — the alleged disclaimer of “sip and spit” dispensing during the prosecution of the ’052 application does not apply to the asserted claims of the ’861 patent.