Finding Cancer Where It Hides
The earlier cancer is found, the more lives are saved. Plasma-Sieve is built for that window.
The Stochastic Sampling Problem
At early cancer stages, tumor-derived cfDNA may represent a fraction of a percent of total circulating cfDNA, with variant allele frequencies (VAF) as low as 0.001% or lower. At these concentrations, whether a mutant molecule is present in any given 10 mL blood draw is a matter of chance, not certainty.
This is not a sequencing problem or a bioinformatics problem. It is a sampling problem. If the mutant molecule is not in your tube, no assay can find it. Plasma-Sieve addresses this directly by sampling a far greater fraction of the circulating cfDNA pool.
Variant Allele Frequency (VAF)
VAF is the proportion of DNA molecules at a given position that carry the cancer-associated mutation. A VAF of 0.1% means one mutant molecule per 1,000 total. At early stages, VAF can be 10x to 100x lower than this, making detection with a small input essentially impossible by chance.
Population Screening Implications
For a screening test to be useful in an asymptomatic population, it must detect cancer at Stage I or II with high sensitivity and low false positive rates. Both requirements demand more cfDNA input than a standard blood draw provides. Plasma-Sieve shifts that baseline.
High-Confidence Detection at Ultra-Low VAF
By sampling an expanded circulating cfDNA pool, Plasma-Sieve converts a probabilistic detection problem into a deterministic one. At 50x enrichment, the same signal that would be missed in 99% of standard blood draws becomes reliably detectable. At 200x, signals at VAF levels previously considered undetectable become accessible.
This is the foundation for a new generation of MCED tests: not just more sensitive in the laboratory, but meaningfully more sensitive at the clinical stage where it changes outcomes.
Key Outcome
High-confidence MCED screening for cancers with ultra-low VAF, unlocked by sampling dramatically more of the circulating cfDNA pool.