A tested vial is evidence about a vial
Chain of custody, in a regulated setting, begins at sampling. Here it begins when the package arrives.
Medutest
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How a claim degrades between the bench and the listing
The Journal does not treat a badge as evidence and states so wherever it reports one.
Chain of custody, and where it begins
What a laboratory can and cannot know about the provenance, storage history and representativeness of what lands on its bench.
Six words a verification badge would need to mean anything
Lot-level verification with a public report is a real and achievable thing. It exists in this market, on a minority of listings.
How a claim degrades between the bench and the listing
What a verification mark would have to carry to be checkable: a date, a lot, a method, a submitter and a link to the report.
How a claim degrades between the bench and the listing
A badge asserts that something was tested. It does not assert what, when, on whose sample, by what method, or whether the lot on sale is the lot that was tested.
Six words a verification badge would need to mean anything
What a verification mark would have to carry to be checkable: a date, a lot, a method, a submitter and a link to the report.
Sending the same vial twice, under two names
The Journal submitted split samples from single lots to three assay services, under names unconnected to this publication, and published each method alongside each result.
Three services, one lot, and a spread of two and a half points
Two years ago we ran an anonymised version of this comparison and promised a named one. This is it, with every method printed in full.
The badge economy, and what it is actually certifying
What a verification mark would have to carry to be checkable: a date, a lot, a method, a submitter and a link to the report.
We split six vials four ways and posted them
The Journal submitted split samples from single lots to three assay services, under names unconnected to this publication, and published each method alongside each result.
A tested vial is evidence about a vial
A result on one vial generalises to a batch only if the vial was drawn in a way that makes it representative — and nobody records how it was drawn.
Blind duplicates: what happens when a laboratory does not know it is being watched
Two years ago we ran an anonymised version of this comparison and promised a named one. This is it, with every method printed in full.
Why a result on one vial says less than the trade needs it to
A result on one vial generalises to a batch only if the vial was drawn in a way that makes it representative — and nobody records how it was drawn.
Reproducibility, measured rather than assumed
The Journal submitted split samples from single lots to three assay services, under names unconnected to this publication, and published each method alongside each result.
The badge economy, and what it is actually certifying
Every step between the laboratory report and the product page removes information, and the badge is the last step.
What a split-sample exercise can establish, and what it cannot
Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from between-laboratory reproducibility.
Sending the same vial twice, under two names
Two years ago we ran an anonymised version of this comparison and promised a named one. This is it, with every method printed in full.
The named comparison we promised two years ago
The Journal submitted split samples from single lots to three assay services, under names unconnected to this publication, and published each method alongside each result.
Reproducibility, measured rather than assumed
The Journal submitted split samples from single lots to three assay services, under names unconnected to this publication, and published each method alongside each result.