Seer (SEER), Nautilus (NAUT): Proteomics Shifts From Plex Count to Accuracy

Plasma proteomics vendors have long competed on plex count — how many proteins a single panel measures. On earnings calls held on July 28 and August 11, 2026, Nautilus Biotechnology (NAUT) and Seer, Inc. (SEER) both described a different basis for comparison: independent third-party, cross-platform per-target data, and whether an assay can resolve the specific protein form that carries the disease biology[1][2].

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Plex count was a specification the vendor wrote itself

Plasma proteomics measures thousands of proteins at once from a single blood draw, and drug companies and academic labs use it to hunt for disease markers. The industry describes a panel by its "plex" — how many proteins it reads in one run — and that number was the main axis of competition for years. It was also disclosed by the vendor, with no cross-platform, protein-by-protein comparison available to the buyer.

Independent third parties have started publishing per-target results across competing platforms, which removes plex count as a self-declared selling point. Those results cover whether a given protein reads consistently across platforms and which proteins only one platform detects, moving the discussion to the biological origin, robustness and interpretability of the signal. The assays gaining commercial traction are low-plex ones that resolve specific protein variants — different forms of the same protein created by modification or splicing, where the disease biology often sits.

Seer's management laid out this direction on its February 2026 call, saying targeted assays were getting smaller and smaller in plex, and that one commercially successful product measures a little more than 100 proteins, all of them variants that matter in disease[3]. What is new is the externally verifiable comparison data.

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The measured gap, and the pace of targeted assay development

On its August 11, 2026 call, Seer cited an independent study published in Nature Genetics. Researchers used samples from roughly 1,400 individuals of British South Asian ancestry to compare Seer's Proteograph platform against two affinity-based assays — affinity methods use antibody-type probes to capture specific proteins, and both Olink and SomaScan belong to that class. Using machine learning models trained on assay characteristics, only 13.5% of Proteograph targets were judged unlikely to achieve cross-platform concurrence, against 39% for SomaScan and over 45% for Olink; Proteograph also measured more than 3,400 proteins neither of the other platforms could detect and drove more than 600 new genetic protein associations[1].

Nautilus Biotechnology said on its July 28, 2026 call that development of its protein-variant assays is now constrained by headcount and capacity rather than by scientific uncertainty. The comparison management gave: the first tau assay (tau is a protein associated with neurodegenerative disease) took about five years, while the first oncology markers reached the same technical bar in about a year[2]. Taken together, the two disclosures support the view that variant-resolving targeted assays can now be produced on a cadence.

On the same call, Seer disclosed a set of intellectual-property developments. In March, the U.S. Patent Trial and Appeal Board upheld key commercially relevant patent claims challenged by Bruker subsidiaries; in June, the European Patent Office reached a comparable decision after a challenge by another party. Seer, together with Brigham and Women's Hospital, also filed a patent infringement complaint against Nanomix, and the U.S. International Trade Commission has formally opened an investigation[1].

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Who publishes the comparison becomes the control point

Once buyers order against third-party per-target data, vendors control one less thing. The specification sheet used to be written by the vendor, and sales could be organized around plex count; now a single external dataset ranks every platform at once, and the procurement conversation starts from published comparison results. What gets tested directly is cross-platform concurrence, so the pressure falls most immediately on the high-plex affinity side.

The patent decisions narrow a different path — the one low-cost imitators use to enter without doing the development work. With claims upheld in two jurisdictions and an ITC investigation open, that entrance is closed for now, and near-term competition is more likely to run among the platforms already in the market[1].

Both third-party studies reached readers as Seer's characterization on its own call rather than as independently opened papers, and the Nature Genetics cohort is roughly 1,400 people of a single ancestry. Nautilus's statement about development cadence is a company expectation about its own capacity, not a delivered result[1][2]. What can be tracked from here: whether further cross-platform comparison studies are published, the outcome of the ITC investigation, and actual orders won by low-plex targeted assays.

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Companies exposed to this change

• Thermo Fisher Scientific (TMO): After acquiring Olink, it is a principal supplier of high-plex affinity proteomics and sits on the side used as the comparator in the third-party work; with cross-platform concurrence data public, whether its panel specifications still support its pricing becomes easier for buyers to test.
• Bruker (BRKR): A scientific instrument maker whose subsidiaries challenged Seer's key patents, giving it a commercial interest in this route; with those claims upheld, its path into or deeper within comparable protein-assay business narrows.
• Quantum-Si (QSI): A single-molecule protein sequencing platform competing for the same drug-company and academic customers; as the purchasing standard moves from protein counts to verifiable per-target performance, its approach faces the same external comparison.

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Sources

[1] Drillr · Seer, Inc. (SEER) · 2026-08-11 · FY2026 Q2 earnings call

[2] Drillr · Nautilus Biotechnology (NAUT) · 2026-07-28 · Q2 2026 earnings call

"Our tau assay took about five years to build. Our first oncology markers reached that same technical bar in about a year."

[3] Drillr · Seer, Inc. (SEER) · 2026-02-26 · FY2025 Q4 earnings call

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