What a certificate of analysis (COA) is and how to read one
A certificate of analysis (COA) is the document an issuing laboratory produces to report the test results applied to a specific batch of a material. For a buying laboratory it is the only documentary evidence that the vial's content matches the label: identity, purity and batch. A COA with no batch number, no stated test method or no identifiable issuing laboratory provides no traceability.
What a certificate of analysis is
A certificate of analysis (COA) is a technical document that records the analytical results obtained for one specific batch of a material. It does not describe the product in general: it describes that batch, produced on a given date and tested with stated methods.
In the market for research reference materials, the COA is the central document of the relationship between supplier and buying laboratory. Materials with no documentation, or with documentation that cannot be verified, are offered in this market, so for a laboratory, knowing how to read a COA is a purchasing competency, not a formality.
What fields a useful COA must carry
A complete COA for a peptide reference material typically includes the fields below. The right-hand column is what is worth checking for each one.
| Field | What it declares | What to check |
|---|---|---|
| Material name and code | Declared identity of the content | That it matches the vial label exactly and the reference purchased |
| Batch number | The production unit that was tested | That it matches the batch printed on the vial received |
| Identity | Confirmation that the material is what it is declared to be | The method used, typically mass spectrometry |
| Purity | Proportion of declared material versus impurities | The method, typically HPLC, and the batch's own figure, not a generic catalog value |
| Test method | How each measurement was obtained | That the method is named, not only the figure |
| Issuing laboratory and date | Who tested it and when | That it is identifiable and reachable; the date should be after the batch was manufactured |
| Storage conditions | How to keep the material | Consistency with the declared physical form, lyophilized or solution |
What HPLC purity measures, and what it does not
High-performance liquid chromatography (HPLC) separates a sample's components and quantifies what proportion corresponds to the declared compound. HPLC purity indicates what fraction of the chromatographic signal belongs to the main compound.
Its scope matters: HPLC purity alone does not confirm identity, because two different compounds can co-elute; it does not necessarily measure water content or residual salts; and it says nothing about sterility or fitness for any specific use. That is why a serious COA combines chromatographic purity with identity confirmation by mass spectrometry, which verifies that the observed molecular mass matches the declared structure.
How to verify a COA is authentic
Three practical checks, in order of effort:
- Internal consistency. Batch number, dates and material name should agree across the COA, the vial label and the purchase document. A product-level COA, with no batch, is not verifiable by construction.
- Identifiable issuing laboratory. A laboratory that issues measurements has a name, a location and a contact channel. Testing laboratories operate under technical-competence schemes such as ISO/IEC 17025, and in Colombia accreditation is granted by the National Accreditation Body of Colombia (ONAC). An issuer not being accredited does not invalidate its COA, but being identifiable and verifiable is a minimum traceability requirement.
- Direct verification. For a significant institutional purchase, the buying laboratory can contact the issuing laboratory, citing the batch number and the document, to confirm the COA was issued by them. This is a standard step in reference-material purchasing and distinguishes suppliers that operate with real documentation.
Manufacturer COA or independent-laboratory COA
A manufacturer's COA documents the production quality control; it is standard, legitimate practice. An additional assay from an independent laboratory adds third-party verification unrelated to the batch's production. The two documents answer different questions, and neither replaces the other. What an institutional buyer should require in every case is that the document be batch-specific, with a stated method and an identifiable issuer.
What a COA does not certify
A COA is not a sanitary/marketing registration, it is not a marketing authorization, it does not certify sterility unless it includes that specific test, and it does not authorize any use outside the one declared for the material. Research-grade reference materials are supplied exclusively for scientific and laboratory research use; batch quality documentation does not change that framework.
Frequently asked questions
- Is a COA with no batch number useful for an institutional purchase?
- It provides no traceability: without a batch there is no way to link the document to the vial received. For an institutional purchase, the COA must correspond to the batch delivered.
- What purity is declared for a peptide reference material?
- Purity is declared per batch and per method, not as a catalog-wide figure valid for the whole inventory. The correct approach is to read the specific batch's figure and the method used to obtain it. A published figure with no batch and no method is not verifiable.
- Can any laboratory issue the COA?
- It can be issued by the manufacturer or by a contracted laboratory. What is verifiable is not the issuer's category but its identifiability, the stated method, and the ability to confirm the document directly with whoever issued it.
- Where is the COA for a reference in this catalog?
- Each reference's analytical data comes from its batch's certificate of analysis. While a given batch's certificate is not available, those fields appear on the technical sheet declared as pending, with the reason stated, and can be requested through the institutional quotation process.
Sources
Related catalog references
Catalogued references from the families this document covers. Each sheet states presentations, current public price, and what batch documentation can be requested.
- 5-amino-1mqsmall molecule that inhibits the NNMT enzyme · Metabolic research peptides
- CJC-1295 without DAC 5mg + Ipamorelin 5mgGHRH analog and secretagogue pentapeptide in the same vial · GH/IGF-1 axis and secretagogues
- B7-33single-chain peptide derived from relaxin-2 · Tissue signaling and extracellular matrix
- Adipotidepeptidomimetic with a prohibitin-binding domain · Metabolic research peptides
- Follistatinactivin-binding glycoprotein · GH/IGF-1 axis and secretagogues
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Last reviewed: 2026-09-25. This site presents a technical catalog of references intended exclusively for research, technical or laboratory purposes. The published information is not medical advice, a prescription or a diagnosis, and the references are not for human or veterinary use. The availability, import, sale and dispatch of any reference are subject to document validation and to the health, customs and regulatory rules that apply in Colombia and in the destination country.