Single‑Reference Disclosures and the Motivation‑to‑Combine Requirement
In January 2026, the Federal Circuit issued a nonprecedential opinion in Guardant Health, Inc. v. University of Washington (Slip Op. 2024-1129, Jan. 23, 2026) that, while not binding precedent, is nevertheless highly relevant to patent practice in any technology. The patent at issue, U.S. Patent No. 10,760,127, claims methods for reducing sequencing errors using Duplex Consensus Sequencing (DCS), a technique that pairs double-stranded DNA with unique molecular identifiers before amplification and sequencing. This approach is designed to achieve unprecedented sensitivity in detecting rare variants, a capability critical to applications like early cancer detection and other high-stakes medical diagnostics.
Guardant had challenged the patent before the Patent Trial and Appeal Board (PTAB), arguing that the claims were obvious under 35 U.S.C. § 103, over a combination of references. The elements at issue were:
b) amplifying original strands of at least a portion of the double-stranded adapter-DNA molecules to produce first and second strand copies;
c) sequencing a plurality of first and second strand copies to obtain first and second strand sequence reads for at least a portion of the adapter-DNA molecules;
Slip Op. at 4.
Guardant argued that these two claim elements were disclosed together in a single embodiment in a prior art reference, U.S. Patent Application No. 2009/0298075 A1[1] (Travers ’075). Travers ’075, while primarily directed to PacBio’s SMRT sequencing, expressly described in a single paragraph performing rolling circle replication (RCR) to produce repeated sense and antisense strands, followed by sequencing those amplified products. Washington countered with Travers 2010[2], another publication from PacBio scientists. Travers 2010 described the SMRTbell template, a topologically circular DNA structure with a double-stranded region and single-stranded hairpin loops, which can be sequenced using SMRT technology without any amplification step. In Washington’s view, the general teaching in Travers 2010 that SMRT sequencing does not depend on amplification reinforced their argument that a skilled artisan would need additional motivation to incorporate RCR amplification before SMRT sequencing and might doubt the feasibility of such a combination.
The PTAB agreed with Washington, concluding Guardant had not shown a motivation to combine the amplification concept from Travers ’075 with the sequencing process of SMRTbell templates as taught in Travers 2010, nor a reasonable expectation of success in doing so.[3] But the Federal Circuit disagreed, explaining that when claim elements appear together in one embodiment of a single reference, here, amplification and sequencing in Travers ’075, no separate “motivation to combine”[4] or “reasonable expectation of success”[5] analysis is required as if the elements originated from disparate sources. Because Guardant’s petition relied on a single paragraph of Travers ’075 itself, and not on modifying the SMRT sequencing process described in Travers 2010, the PTAB’s approach was legally erroneous. The court vacated the PTAB’s ruling and remanded for consideration of whether Travers ’075’s RCR-plus-sequencing disclosure was enabled, a separate requirement for relying on it in an obviousness analysis.
Two key takeaways emerge from the opinion. First, in the context of obviousness, if all disputed claim limitations are disclosed together in one embodiment in a single prior art reference, the analysis does not require a separate finding of motivation to combine those elements. Treating co-disclosed steps as if they came from isolated references improperly burdens the challenger and can distort the obviousness inquiry. Second, even when a prior art reference makes only brief mention of a process or embodiment, in this case, rolling circle replication followed by SMRT sequencing, that disclosure remains prior art “for all that it teaches.” Whether that disclosure is enabled is a separate question that must be addressed before relying on it to establish obviousness.
Now is the perfect time to reassess ongoing patent challenges and diligence frameworks to ensure internal strategies fully reflect this clarified standard. To ensure your patent strategy is ahead of the game, contact your Foley attorney for guidance and to proactively review your portfolio.
[1] U.S. Patent Application No. 2009/0298075 A1
[2] Travers et al., A Flexible and Efficient Template Format for Circular Consensus Sequencing and SNP Detection, 38 Nucleic Acids Research e159 (2010)
[3] Slip Op. at 8.
[4] Slip Op. at 9.
[5] Slip Op. at 13.
