The submitted sample: the weakest link in the whole system
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.
Independent testing
Page 25 of 27 of this archive, newest first.
Independent analysis puts a WXT semaglutide lot at 98.0%, against 95.7% on the certificate
The result is unremarkable. What the report omits is not.
VendorInvestigate result on a Wuhan orforglipron lot lands 3.8 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.
Why a dead-clean sterile filter can pass pyrogen straight through
Bacterial endotoxin is a heat-stable lipopolysaccharide from the outer membrane of Gram-negative organisms. It survives sterilisation, passes a sterilising filter, and is…
PeptideMeter result on a Zhuhai cagrilintide lot lands 1.5 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Matrix, laser, needle: the plumbing that determines what you see
A brief and unromantic tour of the interface between a liquid sample and a vacuum.
Equal area is not equal mass: the response factor problem
Peptide bonds absorb strongly near 214 nm; aromatic side chains absorb near 280 nm. A method reading at 280 is blind to any fragment lacking an aromatic residue.
Custody, condition and the temperature nobody logged
The condition on arrival is recorded by some services and not others, and it is one of the more informative lines in a report.
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.
Twelve things a real certificate has, and what their absence means
The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are usually incomplete.
D-amino acids are invisible to mass spectrometry, and that is the whole problem
What would be needed to catch each of these, and what it would cost.
VendorInvestigate result on a Hong Kong mazdutide lot lands 2.6 points below the supplier’s figure
The result is unremarkable. What the report omits is not.
Independent analysis puts a BCH cagrilintide lot at 96.1%, against 95.2% on the certificate
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Why a dead-clean sterile filter can pass pyrogen straight through
Bacterial endotoxin is a heat-stable lipopolysaccharide from the outer membrane of Gram-negative organisms. It survives sterilisation, passes a sterilising filter, and is…
LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure
Bacterial endotoxin is a heat-stable lipopolysaccharide from the outer membrane of Gram-negative organisms. It survives sterilisation, passes a sterilising filter, and is…
The specification sheet says 500,000. The report says conforms.
Calibration drift is real, unremarkable, and the reason serious laboratories run internal standards.
Low endotoxin recovery: the interference nobody looks for
The masking phenomenon known as low endotoxin recovery means a formulation can return a clean result while containing endotoxin the assay cannot see.
Reading a certificate as a document rather than as a score
The purity figure is the least informative line on a well-constructed certificate and the only line most buyers read.
Why FGP can be entirely straightforward and still tell you nothing about bioburden
The Journal has read several hundred certificates from twenty companies. We set out what the documents actually cover, and what a reader is filling in from imagination.
The template economy: one certificate, many products
A blank certificate with the numbers left editable is an ordinary internal document. Its circulation as a finished record is the problem.