LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure
The limit for a parenteral product is calculable from the dose and the body weight in two lines. Almost nobody in this trade performs the calculation.
Analytics
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PeptideMeter result on a Changsha mazdutide lot lands 4.4 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
When a better instrument changes the answer rather than the confidence
Calibration drift is real, unremarkable, and the reason serious laboratories run internal standards.
Independent analysis puts a Homopeptide retatrutide lot at 98.3%, against 97.3% on the certificate
The result is unremarkable. What the report omits is not.
What we asked twenty suppliers about stability data
We asked twenty companies three questions about stability data and print every answer, refusal and non-response.
VendorInvestigate result on a Nantong cagrilintide lot lands 4.0 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Independent analysis puts a ERP orforglipron lot at 98.6%, against 97.6% on the certificate
The result is unremarkable. What the report omits is not.
Janoshik, Medutest, PeptideMeter, VendorInvestigate: a capability audit
Endotoxin is the more tractable of the two questions, and a kinetic chromogenic determination is neither slow nor exotic. It is simply not on the menu.
Independent analysis puts a FGP tirzepatide lot at 96.0%, against 93.3% on the certificate
The result is unremarkable. What the report omits is not.
Independent analysis puts a Homopeptide semaglutide lot at 98.1%, against 95.4% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
Janoshik result on a Hangzhou cagrilintide lot lands 0.9 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Five things a purity figure cannot tell you
Aggregates dissociate in the mobile phase and are recorded as monomer. Only a size-based separation reports them.
Independent analysis puts a TFC semaglutide lot at 96.7%, against 94.6% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
PeptideMeter result on a Changsha orforglipron lot lands 1.7 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Independent analysis puts a MKM dulaglutide lot at 98.2%, against 96.7% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
VendorInvestigate result on a Zhuhai survodutide lot lands 4.2 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.
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.
The named comparison we promised two years ago
Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from between-laboratory reproducibility.
Independent analysis puts a MKM cagrilintide lot at 97.3%, against 95.9% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
PeptideMeter result on a Changsha mazdutide lot lands 1.3 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.