Same material, different gradients, different answers
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.
Medutest
Page 2 of 5 of this archive, newest first.
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.
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.
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.
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
Lot-level verification with a public report is a real and achievable thing. It exists in this market, on a minority of listings.
What a laboratory knows about the material it receives
Chain of custody, in a regulated setting, begins at sampling. Here it begins when the package arrives.
An interlaboratory comparison nobody had run
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.
Same material, different gradients, different answers
Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from between-laboratory reproducibility.
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.
Chain of custody, and where it begins
The condition on arrival is recorded by some services and not others, and it is one of the more informative lines in a report.
Who chose the vial that was tested?
What a laboratory can and cannot know about the provenance, storage history and representativeness of what lands on its bench.
What a split-sample exercise can establish, and what it cannot
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.
Custody, condition and the temperature nobody logged
What a laboratory can and cannot know about the provenance, storage history and representativeness of what lands on its bench.
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.
The badge is about a sample. The listing is about a product.
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.
How a claim degrades between the bench and the listing
Every step between the laboratory report and the product page removes information, and the badge is the last step.
The named comparison we promised two years ago
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.
How a claim degrades between the bench and the listing
Every step between the laboratory report and the product page removes information, and the badge is the last step.