Glossary
Certificate of analysis (COA)
Also called COA, CoA, Lab report, Third-party test, Test certificate
A document from a testing lab that reports what was measured in a sample: usually identity, purity and sometimes amount and contamination tests.
In more detail
A COA is only as useful as what it measures and whether it matches your vial. A typical peptide COA shows an HPLC purity percentage and a mass spectrometry identity result. Better ones also report the amount found in the vial versus the label and an endotoxin result.
Things to check: the lab name and contact details, a date, a batch or lot number that matches your vial, the method behind each number, and the actual chromatogram or spectrum rather than just a pass stamp.
Why it matters
A high purity number on its own does not tell you how much peptide is in the vial, or whether it is sterile. Read How to read a peptide lab report (COA) before trusting one.
Related terms
- HPLC purityThe share of the peptide signal in a sample that is the target peptide, measured by high-performance liquid chromatography. It is the percentage most COAs lead with.
- Mass spectrometryA test that measures the mass of molecules. On a peptide COA it confirms identity: the measured mass should match the expected mass of the peptide.
- Net peptide contentThe share of a powder's weight that is actually peptide, after water, salts and counterions are excluded. It tells you how much peptide is really in the vial.
- EndotoxinFragments of bacterial cell walls that can cause fever, chills and flu-like reactions when injected. Sterilizing a product does not remove them, so they are tested for separately.
- Research use only (RUO)A label sellers put on compounds that are not approved drugs, stating they are sold for laboratory research and not for human use.
Sources
Each source is labeled by where the information comes from. How we label sources
- Reference workCertificate of analysis(opens in a new tab)
Wikipedia · checked
- Vendor guideWhat is peptide purity?(opens in a new tab)
LifeTein · checked
- RegulatoryGuidance for industry: Pyrogen and endotoxins testing, questions and answers(opens in a new tab)
FDA · checked
Updated