flowchart LR A["1 · Establish assay<br/>quality + pre-analytics"] --> B["2 · Compare tissue and<br/>plasma methylation"] B --> C["3 · Add tissue-of-origin<br/>deconvolution"] C --> D["4 · Evaluate fragment<br/>features"] D --> E["5 · Integrate methylation,<br/>sIgA + inflammation"] E --> F["6 · Validate in an<br/>independent cohort"] classDef base fill:#e9f5f2,stroke:#167d78,color:#123b5d; classDef advanced fill:#f7efe1,stroke:#c58b2c,color:#3c2d16; classDef validation fill:#123b5d,stroke:#123b5d,color:#fff; class A,B,C base; class D,E advanced; class F validation;
Liquid-biopsy technology landscape
More information from every cfDNA molecule
Modern liquid biopsy no longer asks only whether a mutation is present. Methylation, fragment size, fragment ends, nucleosome footprints, topology, and sequence variation can each carry information about disease and tissue of origin (Lo, Han, Jiang, and Chiu, 2021; Tsui, Jiang, and Lo, 2025). These technologies provide a roadmap for this project’s cfDNA work—but most were developed in cancer cohorts and cannot be assumed to perform similarly in ulcerative colitis.

Leading laboratories
| Institution / group | Research leaders | Distinctive contribution | Relevance here |
|---|---|---|---|
| Johns Hopkins Kimmel Cancer Center | Victor E. Velculescu; Robert B. Scharpf and collaborators | DELFI uses genome-wide cfDNA fragmentation patterns; GEMINI models genome-wide mutation profiles from single cfDNA molecules. Their combination illustrates multi-feature detection. | Fragmentation could complement methylation when inflammation, tissue injury, and neoplasia all contribute cfDNA. |
| CUHK Li Ka Shing Institute / Chemical Pathology | Y. M. Dennis Lo; Rossa W. K. Chiu; Peiyong Jiang | Foundational work in plasma DNA biology, fragment ends, topology, genome-wide methylation, and tissue-of-origin mapping. | Directly informs the challenge of deciding whether a plasma methylation signal originates in colon, blood cells, or another tissue. |
| UCLA Zhou Lab | Xianghong Jasmine Zhou; Wenyuan Li and collaborators | CancerLocator, CancerDetector, cfTools, and cost-conscious cfDNA methylation analysis for detection and tissue localization. | Offers computational precedents for read-level signal amplification and methylation-based deconvolution. |
| Stanford Oncology | Maximilian Diehn; Ash Alizadeh; Billy Lau; Hanlee Ji and collaborators | CAPP-Seq established ultrasensitive targeted ctDNA tracking; later native nanopore work jointly measures methylation and fragment length on individual cfDNA molecules. | Shows a path from single-feature assays toward joint molecular profiles, although platform feasibility must be assessed locally. |
| Tagomics | Jack Kennefick; John Gallon; academic and pharmaceutical collaborators | Activace enriches informative unmethylated regions; LiquiPath uses cell-type methylation atlases and deconvolution for multi-organ safety monitoring. | Demonstrates how tissue-specific reference atlases could make a blood signal more biologically interpretable. |
Platform comparison
| Platform | Signal used | Technical idea | Current application | Key caution |
|---|---|---|---|---|
| DELFI | Fragment sizes and genome-wide fragmentation patterns | Low-coverage whole-genome sequencing plus machine learning | Cancer detection and treatment-monitoring research | Fragmentation is affected by biology and pre-analytics; a cancer-trained classifier is not a UC classifier. |
| GEMINI | Genome-wide mutation patterns in individual molecules | Machine learning aggregates sparse mutation information | Early cancer detection research, including combination with DELFI | Somatic mutation burden and epigenetic dysregulation are different biological signals. |
| CancerLocator / CancerDetector | cfDNA methylation | Probabilistic tissue localization and joint CpG-pattern modeling at read level | Research in early cancer detection and localization | Reference methylomes, population transferability, and low tumor fraction determine performance. |
| Galleri | Targeted cfDNA methylation | Genomic sequencing, data science, and machine learning predict a cancer signal and likely origin | Commercial multi-cancer early detection test; signals across more than 50 cancer types | It complements rather than replaces recommended screening and does not detect every cancer. It is not validated for UC progression surveillance. |
| Native nanopore cfDNA | Methylation plus physical fragment length on the same molecule | PCR-free, single-molecule sequencing preserves linked epigenetic and fragmentomic features | Emerging cancer-detection research | Evidence is still developing; input, depth, error profiles, cost, and independent validation matter. |
| LiquiPath / Activace | Cell-type-specific methylation and unmethylated-region enrichment | Atlas-based deconvolution traces plasma cfDNA to contributing tissues | Early-access drug-safety and organ-injury monitoring | Proprietary platform; company-reported capabilities need independent, use-case-specific validation. |
A practical technology ladder for this project
This sequence prevents technology from outrunning the biological question. With a modest exploratory sample, priority should go to reproducible sample handling, assay QC, pre-specified comparisons, and effect-size estimation. High-dimensional machine learning is most credible after sample size and external validation support it.
Design lessons that transfer
- Preserve provenance. Record collection tube, processing delay, centrifugation, storage, freeze–thaw history, DNA yield, library batch, and sequencing metrics.
- Model tissue of origin. Plasma is a mixture; methylation references and paired colon tissue can help separate epithelial biology from leukocyte or systemic signals.
- Keep features linked when possible. Single-molecule approaches can connect methylation and fragment length instead of measuring them in separate aliquots.
- Control the analytical search space. Small cohorts favor pre-specified regions, pathway-level summaries, shrinkage, and resampling over unconstrained classifiers.
- Separate discovery from validation. Internal cross-validation estimates model stability; it does not substitute for a new cohort, prospective follow-up, or clinical-utility testing.
Open the literature review → · Where this could fit in a clinic →
These platforms demonstrate what cfDNA can reveal in oncology and organ-injury settings. Their inclusion is a technology landscape, not evidence that they diagnose UC, predict colitis-associated CRC, or outperform colonoscopic surveillance.