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.
Peptide content
Page 6 of 10 of this archive, newest first.
Counter-ion, water, salt: three masses with no chromatogram
An orthogonal method separates on a different physical principle, so that species co-eluting in the first are likely to resolve in the second. Two runs of the same method at…
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.
At 214 nanometres you see every peptide bond. At 280 you see three residues.
Area per cent silently assumes that every species in the sample absorbs as strongly per unit mass as the parent. For peptide impurities that assumption is usually wrong, and…
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.
One method is one opinion
An orthogonal method separates on a different physical principle, so that species co-eluting in the first are likely to resolve in the second. Two runs of the same method at…
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.
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 far back does this document actually reach?
What happens to traceability when bulk material is subdivided, repackaged and relabelled two or three times before sale.
Check the vial, not the box
A document is only as good as the chain that connects it to the material, and most chains here are two or three links longer than the paperwork admits.
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.
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.
Who chose the vial that was tested?
Every third-party report in this market describes a sample somebody chose to send. That choice is outside the laboratory’s control and outside its records.
How far back does this document actually reach?
A document is only as good as the chain that connects it to the material, and most chains here are two or three links longer than the paperwork admits.
Repackaging, subdivision, and the batch number that changed hands
A document is only as good as the chain that connects it to the material, and most chains here are two or three links longer than the paperwork admits.
What a laboratory knows about the material it receives
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
Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from between-laboratory reproducibility.
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.
The batch number is the only thing connecting the page to the vial
The interval between manufacture and analysis is the most under-read figure on the page, and the one most likely to matter by the time a vial is opened.
What the nitrogen said
Peptide content is the number that tells you how much drug is in the vial. Almost nobody sells it, almost nobody buys it, and when we paid for it on nine vials the results…