The rule
Every lot of every compound we supply is sampled and sent to an independent laboratory before it is listed. The laboratory measures purity by reversed-phase HPLC and confirms identity by LC-MS, and where the compound warrants it, endotoxin by LAL and net peptide content. The signed report is uploaded to the certificate register, the figures are transcribed beside it, and only then is the batch released for sale. A size with no released batch cannot be added to the basket, and the product page says so.
Nothing is available "on request". If a vial has shipped, its certificate is public, searchable by the batch number printed on the label.
What a certificate contains
Each certificate names the laboratory and its report reference, the batch number, the compound and vial size, the test date, the purity figure and the method it came from, the observed mass against the expected mass, and the endotoxin and net content results where tested. The register shows the same figures in a table so that batches can be compared, and each batch has its own page with the PDF embedded.
How we test explains each method and our acceptance criteria. The laboratory describes who does the testing and what we require of them. Reading a certificate of analysis walks through a report line by line.
Acceptance criteria
| Test | Method | Criterion |
|---|---|---|
| Purity | RP-HPLC, C18, UV at 220 nm | Main peak ≥ 99.0 % of total peak area |
| Identity | LC-MS, electrospray | Deconvoluted mass within ± 1.0 Da of theoretical (± 0.5 Da for peptides under 2,000 Da) |
| Endotoxin | LAL, kinetic chromogenic | Reported in EU/mg; where tested, ≤ 1.0 EU/mg |
| Net peptide content | Amino acid analysis or UV | Reported where tested; informs concentration calculations |
| Appearance | Visual | Uniform lyophilised cake, no discolouration, intact seal |
A batch that fails any criterion is not released. A batch that is withdrawn after release stays in the register, marked as withdrawn, so that the record is complete.
What we do not claim
We do not claim sterility unless a certificate states a sterility test was performed. We do not claim that any compound is suitable for any use beyond in-vitro laboratory research. We do not use a site-wide purity figure in place of the batch figure; the number on the product page is the number on the report for the batch currently shipping.
Manufacturing
Compounds are synthesised to order by solid-phase peptide synthesis, purified by preparative HPLC, lyophilised and sealed under nitrogen in Type I glass vials with bromobutyl stoppers and aluminium flip-off crimps. The batch number is assigned at lyophilisation and printed on every label.