Laboratory procurement documentation
Understanding peptide Certificates of Analysis
A Certificate of Analysis (COA) records results for the sample described in a laboratory report. Read the method, units and sample record together: a single percentage cannot answer every quality question.
Purity, identity and content are different measurements
| Reported measurement | What to check | What not to assume |
|---|---|---|
| Chromatographic purity | If expressed as peak-area percentage, it describes the relative signals detected under that method's conditions. | It is not, by itself, the mass of peptide in a vial or a complete account of all impurities. |
| Identity | Check which identification method was used, its reported result and comparison with the expected compound. | A purity percentage alone does not establish molecular identity. |
| Measured content | Look for a quantitative assay, its units, sample basis and any stated uncertainty or limitations. | The nominal strength on the listing is not a measured-content result unless the report establishes it. |
Peptide quantification can use different methods and reference standards. Results should be interpreted within the laboratory's stated scope, not treated as interchangeable numbers.
Match the report to the supplied material
- Check the compound, presentation, report reference, laboratory and test date.
- Compare the report's sample identifier with the available product and order documentation.
- Review the tested sample, methods, units and any limitations stated by the laboratory.
- If the link between the supplied material and the tested sample is unclear, ask for clarification before relying on the result.
A report describes the tested sample; it is not evidence that every individual vial has been tested. Retain the original document with the relevant procurement record.
A COA is not an approval for human use
A purity or identity result does not establish sterility, endotoxin levels, clinical safety, effectiveness or regulatory authorisation. Those conclusions require their own appropriate evidence and assessment.
Core Peptides supplies products for lawful laboratory research only, not for human or veterinary use. This guide provides no dosing, administration or treatment instructions.
Find the relevant product documentation
Product pages show available COA links, stated specification, storage information and stock or lead time. If a document is not shown, contact order support before ordering. Order-specific documents, where available, are retained with the order record.
Further analytical reading
These independent references explain measurement approaches; they are not endorsements of Core Peptides or certificates for our products.
- NIST: survey of peptide quantification methods and reproducibility
- BIPM: peptide and protein purity measurement
Reviewed 1 October 2026. For questions about an individual result, consult the issuing laboratory.