Why a 0.036-dalton difference is the hardest number in peptide identity
Calibration drift is real, unremarkable, and the reason serious laboratories run internal standards.
Analytics
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Medutest result on a Chengdu cagrilintide lot lands 4.4 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
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…
Independent analysis puts a FGP mazdutide lot at 98.8%, against 96.2% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Pore size, particle size, and why peptides need the wide pores
Ion-pairing additives sharpen peptide peaks and suppress ionisation in the mass spectrometer, which is why the purity method and the identity method are often not the same…
The reviewer, the approver, and why regulated documents carry two names
A manufacturer’s certificate is a self-declaration. An accredited laboratory’s report is a third-party measurement. The trade prints both under one heading.
Independent analysis puts a FGP survodutide lot at 95.6%, against 92.9% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
PeptideMeter result on a Tianjin retatrutide lot lands 3.7 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
Adsorption, and the dose that stayed on the glass
An in-use period is established by a dedicated study on a specific formulation in a specific container at a specific concentration. Borrowing one from a marketed product is…
Independent analysis puts a CPC dulaglutide lot at 96.5%, against 94.8% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
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.
The four testing services and the study none of them can run
We asked twenty companies three questions about stability data and print every answer, refusal and non-response.
Size exclusion sees the thing reversed-phase dissolved
Where two methods disagree, the conservative convention is to report the lower figure. It is not universal, and whether a laboratory follows it belongs on the report.
Janoshik result on a Chengdu 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.
Medutest result on a Zhuhai 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.
Medutest result on a Qingdao dulaglutide lot lands 1.4 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
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.
Independent analysis puts a ERP exenatide lot at 95.8%, against 93.5% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
Independent analysis puts a KP semaglutide lot at 95.6%, against 94.1% on the certificate
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The badge is about a sample. The listing is about a product.
The Journal does not treat a badge as evidence and states so wherever it reports one.