Independent study validates the SomaScan Assay as the most precise and comprehensive plasma proteomic platform
The SomaScan Assay: The best platform available for discovery studies, confirmed by competitive analysis
A recent independent study by Alkahest, published as a preprint on bioRxiv1, compared the technical precision and performance of multiple plasma proteomic platforms using a common set of samples.
Key findings
- The SomaScan™ 11K and 7K Assays outperformed all competitors in precision, breadth of coverage and biological relevance
- The SomaScan 11K Assay delivered the lowest coefficient of variation (%CV), demonstrating superior reproducibility
- The SomaScan Platform enables 11,000 protein measurements, covering half of the genetically encoded human proteome, offering unmatched plasma proteomic coverage
Platforms evaluated included those from Olink, Seer, Biognosys and Thermo Fisher. Across all key metrics, the SomaScan Platform delivered the most reproducible, comprehensive and biologically relevant data, reinforcing its status as the premier choice for large-scale plasma proteomics.
Highest precision:
The SomaScan Assay delivers the lowest %CV
A key indicator of reliability in proteomics is %CV, a statistical measure of the consistency of repeated measurements. The lower the %CV, the more reproducible the results2.
The study’s authors used duplicate samples from 78 healthy donors to assess precision for seven proteomic platforms (Table 1), which is by our understanding the largest number of proteomic platforms ever compared on the same sample cohort.
Results:
- The SomaScan 11K Assay had the lowest median %CV (5.3%), demonstrating unmatched precision and reproducibility
- The SomaScan 7K Assay followed closely at 5.8%, ensuring version-to-version consistency
- In stark comparison, the 3k and 5k assays from Olink showed significantly higher variability, with %CVs of 11.4% and 26.8%, respectively, up to five times higher than the SomaScan 11K Assay
These findings align with previously reported CVs for the SomaScan 11K Assay3 and SomaScan 7K Assay4, as well as results from earlier head-to-head comparison using ARIC data5.
Beyond precision: Unmatched coverage of the circulating proteome – more proteins, more reliable data
The SomaScan Platform doesn’t just excel in precision, it also delivers the most complete proteomic data. With 11,000 proteins measured, the SomaScan 11K Assay covers half of the genetically encoded human proteome.
However, achieving this level of detection is a challenge due to the wide dynamic range of protein abundances in plasma. Many broad-scale proteomic platforms fail to overcome this barrier. Yet, in this study:
- 96.2% of analytes on the SomaScan 11K Assay had signals above the detection threshold in heathy plasma samples
- 95.8% of analytes on the SomaScan 7K Assay met the same threshold
- Competing proteomic platforms showed significantly lower data completeness, ranging from 35.9% to 60.3%
This means researchers can trust the SomaScan data for consistent, reliable results across all assay versions, without the data gaps seen in competing platforms.
Table 1. Performance metrics of proteomic platforms [adapted from Kirsher, D.Y. et al. bioRxiv (2025)]
| Proteomic Platform | No. of Unique Proteins | Median & CV (technical variance) | Data Completeness |
|---|---|---|---|
| SomaScan 11K Assay | 9,852 | 5.3% | 96.2% |
| SomaScan 7K Assay | 6,467 | 5.8% | 95.8% |
| Olink Explore HT (5k) | 5,416 | 26.8% | 35.9% |
| Olink Explore 3072 (3k) | 2,925 | 11.4% | 60.3% |
| Seer Proteograph | 5,943 | 26.4% | 50.0%* |
| Biognosys TrueDiscovery | 3,575 | 29.8% | 53.6% |
| Thermo Fisher SureQuant | 551 | 8.3% | 50.0%* |
* Data completeness for Seer and Thermo Fisher estimated from Figure 2C.
Biological relevance:
More proteins, more insights
The ability to reliably detect proteins is just one important factor in evaluating a platform. Equally critical is the ability to generate meaningful biological insights.
To assess this, the authors combined clinical data with proteomic readouts to evaluate each platform’s ability to identify biologically relevant protein markers linked to age, sex, BMI, smoking status and race.
While all platforms identified some associations, the SomaScan Platform outperformed all competitors, detecting hundreds to thousands of proteins per clinical measure. Additionally, the SomaScan Platform covered the most FDA-approved biomarkers and covered the highest number of proteins classes as defined by the PANTHER protein classification system with greater depth than any other platform.
Why the SomaScan Platform
is the best choice for plasma proteomics
The field of proteomics is advancing rapidly, offering unprecedented opportunities for biomarker discovery, drug development and disease research. As researchers adopt multi-platform approaches, selecting the right plasma proteomic tool is crucial.
As the authors of the Alkahest study conclude:
[The SomaScan Platform] offers the most comprehensive coverage of the plasma proteome, making it the best platform available for discovery studies with the objective of identifying previously unknown biological roles for the largest set of proteins.”
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References
- Kirsher, D.Y. et al. “The current landscape of plasma proteomics: technical advances, biological insights, and biomarker discovery.” bioRxiv (2025): doi:10.1101/2025.02.14.638375.
- SomaScan Coefficient of Variation White Paper (SL00000873)
- Candia, J. et al. “Variability of 7K and 11K SomaScan plasma proteomics assays.” Journal of Proteome Research 23 (2024): 5,531–5,539.
- Candia, J. et al. “Assessment of variability in the plasma 7K SomaScan proteomics assay.” Scientific Reports 12 (2022): 17147.
- Rooney, M.R. et al. “Plasma proteomic comparisons change as coverage expands for SomaLogic and Olink.” medRxiv (2024): doi:10.1101/2024.07.11.24310161.
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