A peptide Certificate of Analysis, or COA, is most useful when it can be connected to the material a laboratory actually receives. For UK research procurement, our starting question is simple: what does this document establish about this sample, and what is still unknown?
At a glance
- Match the document to the specific product and lot.
- Read the test method alongside the result.
- Check any accreditation claim against its relevant scope.
Start with the product and batch
Our document-review checklist begins with the product identifier, sample or lot reference, testing organisation and report date. Compare them with the supplier listing and, on receipt, the vial or package label. A mismatch is a request for clarification; a familiar logo does not resolve it.
Keep the original report rather than a cropped screenshot. Record where it came from and when you checked it. If the laboratory offers a verification service, use its own website or contact details to confirm the report reference. These are procurement checks we recommend, not a claim that every laboratory uses the same document format.
Read methods and results together
NIBSC’s peptide-library record lists HPLC, mass spectrometry and sequence information as distinct material data. That separation is useful: a purity measurement and an identity-related measurement do not answer the same question. Ask the supplier what each reported method establishes for the sample.
Avoid treating a percentage as a complete account of the vial. Ask what the percentage measures, how the stated content was assigned, and which other attributes were tested. A report can be useful without answering every question; the important point is to make its scope visible.
Check the scope of an accreditation claim
UKAS explains that a fixed accreditation scope defines the activities for which a testing or calibration laboratory has demonstrated competence. If a supplier presents a laboratory’s accreditation as supporting a particular result, check the applicable schedule and method rather than relying on a badge alone.
Accreditation of an activity, a report-verification reference and approval of a finished medicine are separate matters. The label on a supplier page should make clear which of those is being claimed.
A practical review sheet
| Check | What to record | If unclear |
|---|---|---|
| Product and lot | Exact identifiers on the listing, report and received label | Request the batch association |
| Analytical result | Method, units and reported outcome | Ask what the value represents |
| Report provenance | Original file, laboratory and verification reference | Contact the issuing laboratory |
| Scope | Tests covered and any applicable accreditation schedule | Request the relevant scope |
| Decision | Reviewer, date and unresolved questions | Keep approval pending |
Using the Selective Peptides report tree
Our Purity reports section separates supplier-linked documents, verification references and missing-report requests. Some entries carry review notes. A document link is therefore a starting point for assessment, not a promise that a future supplied batch has been approved.
Use the tree to identify what to request, then retain the supplier’s answer with your own procurement record. That creates a clearer paper trail than ranking suppliers by a purity headline alone.
Questions answered
Does a high HPLC percentage prove a product is suitable for every experiment?
No. Suitability depends on the experiment and the attributes measured. Ask which tests are relevant to your laboratory’s requirements.
Does a COA make a research product a licensed medicine?
No. Analytical documentation and medicinal-product status are different questions. UK classification should be checked against current MHRA guidance.
Sources & further reading
Source record assembled for this editorial on 25 October 2026. Research dates are shown separately from our publication date. Live trial status and supplier information may change.
- Peptide library: material data and storage ↗NIBSC / MHRA
- UKAS policy on fixed and flexible scopes ↗United Kingdom Accreditation Service
- Medicinal-product classification guidance ↗MHRA · Updated 2 July 2026
Independent, source-based editorial. No clinical review or affiliation with the cited research institutions is claimed.
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