Reproducibility, measured rather than assumed
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.
Orla McCaffrey
Page 2 of 6 of this archive, newest first.
Archive — page 2
107 piecesThe certificate says 2026. The vial in your hand does not say anything.
What happens to traceability when bulk material is subdivided, repackaged and relabelled two or three times before sale.
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.
Six words a verification badge would need to mean anything
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.
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.
PeptideMeter result on a Zhuhai dulaglutide lot lands 3.7 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Date of analysis, date of manufacture, and the gap between them
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.
Independent analysis puts a GL Biochem semaglutide lot at 97.8%, against 94.6% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
Endotoxin is not a microorganism, and killing the bacteria does not remove it
The masking phenomenon known as low endotoxin recovery means a formulation can return a clean result while containing endotoxin the assay cannot see.
Sterility is not a percentage, which is the whole difficulty
Every certificate circulating in this market answers a question about molecules. Almost none answers a question about organisms, pyrogens, or the integrity of the seal.
What a batch number is supposed to mean
What happens to traceability when bulk material is subdivided, repackaged and relabelled two or three times before sale.
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.
Date of analysis, date of manufacture, and the gap between them
What happens to traceability when bulk material is subdivided, repackaged and relabelled two or three times before sale.
Independent analysis puts a CPC mazdutide lot at 97.5%, against 94.0% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
The header, the table and the signature block
The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are usually incomplete.
Oxidation, and the peroxide that came in with the surfactant
Deamidation, oxidation, aggregation and hydrolysis account for nearly all of what happens to a peptide over time. Each has a characteristic residue, a characteristic…
Who signed this, and what did they undertake by signing it
Accreditation is granted for a defined scope of methods. A laboratory can be properly accredited and the test on your certificate can sit outside it.
Why the independent testing market grew a chemistry arm and not a microbiology one
The absence of microbiological capability in this market is a commercial fact with a straightforward explanation, and it is worth understanding before blaming anybody for it.
Everything on the page, in the order a chemist would read it
The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are usually incomplete.
We split six vials four ways and posted them
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.