idea-003 · user messages

Every line ends in the claim that substantiates it and that claim's own confidence tag, or is marked unsubstantiated. A message set never upgrades a tag, invents a number, or states anything the candidate's intended use does not cover.

Commutable patient-matrix reference material panel for validating tumor-informed ctDNA MRD assays (clinical QC material) — user messages

Intended use: Quality control material — intended for use by molecular laboratories to monitor the analytical performance (analytical sensitivity at defined low tumor fractions, specificity, and inter-run precision) of tumor-informed circulating tumor DNA minimal residual disease assays, during assay validation and in routine run-by-run quality control. Not a calibrator, and not for use in establishing or interpreting an individual patient result.

Messages

What changes on Tuesday: Instead of diluting a DNA mix into your own plasma to make the day's low-level control, you open one single-use vial of pooled human donor plasma, about 0.03% VAF (variant allele frequency) per variant and at least 30 ng of cfDNA (cell-free DNA), and extract it alongside the patient samples in that run. claim 166unconfirmed
What it replaces: Your in-house contrived control — including the common route of diluting the Seraseq ctDNA (circulating tumour DNA) MRD (molecular residual disease) Panel Mix, which ships as four vials of purified DNA in Tris/EDTA buffer at 0%, 0.5%, 0.05% and 0.005% tumor fraction, into your own plasma. claim 111unconfirmed claim 177unconfirmed
Why they would switch: "A control that comes as DNA in buffer skips my extraction. A control in plasma goes through it with my patient samples, so the whole run is being checked, not just the part after extraction." claim 183unconfirmed
One fewer thing to make: An external lot with a stated uncertainty at every level is one fewer material you have to make, characterize and defend yourself. claim 21unconfirmed
The label tells you what a run should contain: The daily control's label states the expected number of tumor-derived variant molecules per extraction and the probability that an in-control run contains none, set so that a run holds at least one mutant molecule at least 95% of the time. claim 160unconfirmed
What is measured and what is derived: Levels at or above 0.1% VAF are quantified by digital PCR. Levels below 0.1% are derived by gravimetric dilution and say so on the label. Published interlaboratory ddPCR work agrees with gravimetric values down to 0.1% and quantifies no lower, and we will not pretend otherwise. claim 100verified
For your LoD study: A multi-level panel with an expanded uncertainty at every level, including dilution, between-unit heterogeneity and a characterized limit-of-blank term — so the number you publish rests on a documented value, not an assumption about your own dilutions. claim 134unconfirmed
Designing your patient-specific panel against it: Every lot ships with a certified variant list, a tumor-proxy DNA and a normal-proxy DNA, in quantities sufficient for the tumor and matched-normal sequencing your assay needs to design against it. claim 162unconfirmed
When the lot changes: Every production lot is built on an independently sourced plasma pool, and a lot is not released unless its daily-control value lands within 20% of nominal with an uncertainty interval that overlaps the lots before it. claim 170unconfirmed
What CLIA (Clinical Laboratory Improvement Amendments) asks of you: CLIA requires you to establish analytical sensitivity before reporting patient results on a test not subject to FDA (US Food and Drug Administration) clearance, and names no material, source or traceability for doing it. This material is one way to meet that requirement, not the required way. claim 76verified
What your inspector may ask: Whether a CAP inspector credits a third-party panel with a published uncertainty budget as evidence for your limit of detection is not something we can tell you yet. claim 24unconfirmed
Regulatory status: A Class II (FDA device class II) quality control material under 21 CFR (Title 21 of the Code of Federal Regulations) 866.5910, product code SCU (subcutaneous), a type FDA lists as 510(k) (premarket notification)-exempt — so it is neither "cleared" nor "approved", and anyone who tells you otherwise has the category wrong. That the exemption applies to this material, rather than merely existing for the code, is an FDA reading not yet obtained. claim 52unconfirmed
What it does not do: It does not show that your assay behaves the same on patient samples. Published work found that some extraction kits recover spiked DNA preferentially over the plasma's own cfDNA; until equivalence data for this material across extraction methods is on the label, extraction recovery is a study you still run yourself. claim 92verified
Where it does not claim precision: At levels where too few mutant molecules reach an extraction, the panel monitors whether your assay detects, not how precisely it measures. Precision is claimed only where the expected count per extraction is at least 100. claim 161unconfirmed

Beyond intended use

Any message above that asserts a population, setting, duration or outcome the intended use does not state. None. is a valid answer and the honest one for most candidates. An absent section is a failure.

None. Checked line by line against the indication; two things were looked at deliberately:

"For your LoD study" stays on monitoring, not calibration. The intended use says "not a calibrator". Anchoring a published limit of detection to a documented value is analytical sensitivity monitoring during assay validation, which the indication names. The copy never says the material sets, adjusts or calibrates the assay, and it must not be edited to.
"Designing your patient-specific panel against it" describes the laboratory designing its assay against the material's own tumor-proxy and normal-proxy DNA — a validation step, not a patient. No message says the material is used on, with, or to interpret any patient's specimen, and What it does not do exists to hold that line.

The setting is the molecular laboratory throughout; no population, duration or clinical outcome is asserted.

What we cannot say yet

Every message above whose backing is not verified. The checker enforces set equality — exactly these lines, no more and no fewer.

What changes on Tuesday: the 0.03% / 30 ng vial is a design condition on a product that has not been built — claim 166unconfirmed
What it replaces: the incumbent's format is from a vendor page no connector reaches, and that labs dilute it into their own plasma is an adoption claim nobody has asked a lab about — claim 111unconfirmed claim 177unconfirmed
Why they would switch: the extraction point is written back today and never checked, and the quote is ours, not a customer's — claim 183unconfirmed
One fewer thing to make: a stated preference with no primary research behind it — claim 21unconfirmed
The label tells you what a run should contain: a labelling design condition on an unbuilt product — claim 160unconfirmed
For your LoD study: no lot and no uncertainty budget exist yet — claim 134unconfirmed
Designing your patient-specific panel against it: no external laboratory has yet designed a panel against a lot of this material — claim 162unconfirmed
When the lot changes: a release criterion for lots that have not been made — claim 170unconfirmed
What your inspector may ask: CAP checklist text has not been read by anyone working on this — claim 24unconfirmed
Regulatory status: the exemption is verified to exist for SCU and not verified to apply to this material — claim 52unconfirmed
Where it does not claim precision: a labelling design condition; the 100-molecule threshold is arithmetic, the product is unbuilt — claim 161unconfirmed

Words on this page10 abbreviation(s) and code(s), with what each stands for — copied from _shared/plain-language.md

21 CFR: Title 21 of the Code of Federal Regulations — the US food-and-drug rulebook; a number after it is one regulation, often the one that classifies a device type
510(k): premarket notification — the FDA route for a device shown to be as safe and effective as one already on the market; months, no clinical trial as a rule
cfDNA: cell-free DNA — DNA fragments floating in the blood, most of them from normal cells
Class II: FDA device class II — moderate-risk devices, usually cleared by 510(k)
CLIA: Clinical Laboratory Improvement Amendments — the US rules a clinical laboratory must meet to report test results on patients
ctDNA: circulating tumour DNA — fragments of a tumour's DNA found in the blood
FDA: US Food and Drug Administration — the US regulator that clears or approves a device before it can be sold
MRD: molecular residual disease — cancer left behind after treatment, too little to see on a scan, detected through DNA in the blood
SCU: subcutaneous — under the skin
VAF: variant allele frequency — what share of the DNA fragments at one position carry the tumour's mutation; the lower it is, the harder the test

Generated from knowledge-base/messaging/idea-003-user.md by engine/scripts/build_review.py on 2026-10-04. This page is a view — edit the source file and rebuild, never edit here.