Knobbe Martens
Aug 8, 2020

Limiting Terms in Preamble May Render Entire Preamble Limiting


Before Newman, O’Malley, and Taranto.  Appeal from the United States District Court for the District of Delaware.

Summary: Where elements of preamble are limiting, indivisible terms in the remainder of the preamble are also limiting; under balance of hardships analysis a permanent injunction should not extend to products for which there are no non-infringing alternatives.

Bio-Rad sued 10X for infringing three patents covering systems for forming microscopic fluid droplets for medical diagnostics and screening.  A jury found 10X liable for willful infringement.  The district court denied 10X’s JMOL motion of noninfringement and granted Bio-Rad’s motion for a permanent injunction. 

On appeal, 10X argued that for two of three patents, the district court misconstrued the independent claims by failing to find the preambles limiting.  The district court found some preamble terms provided an antecedent basis for use of those terms in the body of the claim, but that did not convert the entire preamble into a limitation. The Federal Circuit disagreed.  It determined the preamble could not be neatly divided into separate portions and the preamble must be read together as a whole.  It held the district court erred in giving limiting effect to certain terms in the preamble, but not to other terms surrounding those limiting parts.  The Federal Circuit remanded for a new infringement determination considering the preamble as a whole as limiting the scope of the claims.

10X also challenged the scope of the permanent injunction.  The district court determined that the hardship to 10X was mitigated because it could still generally sell non-infringing alternative systems for some, but not all of the enjoined systems.  The Federal Circuit evaluated 10X’s hardship product-by-product, and vacated the injunction for two of five product lines because those products had no non-infringing alternatives.

Editor: Paul Stewart

Written by: Marissa M. Rosenbaum & Mark Kachner