The four testing services and the study none of them can run
Storage instructions in this market are close to uniform and almost never accompanied by the study that would justify them. Uniformity is a sign of convention, not of…
Purity
Page 40 of 51 of this archive, newest first.
What changed at QST in August, and what the company will not say about it
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
Homopeptide declines, for the 17th time, to name its synthesis house
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
The empty half of every certificate of analysis
Purity, content, identity, sterility and endotoxin are five separate determinations. A single sheet of paper carrying one of them is not evidence about the other four.
What changed at FGP in August, and what the company will not say about it
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
PeptideMeter result on a Wuhan dulaglutide lot lands 1.8 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.
TFC declines, for the 4th time, to name its synthesis house
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
Independent analysis puts a TFC mazdutide lot at 98.1%, against 94.2% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
What the sequence tells you about how a peptide will fail
Reversed-phase chromatography runs in an organic, acidic mobile phase that dissociates most non-covalent aggregates on the way to the detector.
Holograms, QR codes and other things that are not verification
Reported from the analysis, not from a warning notice.
Four ways a peptide comes apart
The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts deamidation; a cysteine predicts disulphide scrambling.
Oxidation, and the peroxide that came in with the surfactant
The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts deamidation; a cysteine predicts disulphide scrambling.
South Korea health authority warns on falsified exenatide pens
Reported from the analysis, not from a warning notice.
VendorInvestigate result on a Tianjin tirzepatide lot lands 0.7 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Ireland health authority warns on falsified semaglutide pens
Reported from the analysis, not from a warning notice.
Holograms, QR codes and other things that are not verification
Reported from the analysis, not from a warning notice.
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.
What changed at FGP in July, and what the company will not say about it
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
PeptideMeter result on a Suzhou retatrutide lot lands 2.2 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
Twenty-eight days is a number from somebody else’s product
We set out what is known, what is inferred and what is simply assumed about the fortnight after a vial is opened.