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RESEARCH LIBRARY

How to Read a Certificate of Analysis

Astra Biolabs Research Library · Updated October 4, 2026

A certificate of analysis, or COA, records analytical findings for a particular sample or batch. Reading it well means checking what was tested, how the result was obtained, and whether the document matches the material being evaluated.

This guide explains report literacy. It does not certify an Astra Biolabs batch or establish suitability for human or veterinary use.

Start with the document and batch

  1. Match the identifiers. Compare the sample name and batch or lot number with the material label. A report for another lot is not evidence for the lot in front of you.
  2. Identify the issuer. Look for the testing laboratory, report number, dates, and authorized approval. Verify authenticity with the issuer when needed.
  3. Find the methods and specifications. A result needs the applicable test method, measurement units, and acceptance criteria to be interpreted.
  4. Read the complete report. Check its page count and any amendments, notes, exclusions, or retest date rather than relying on a cropped screenshot.

WHO’s model certificate includes sample and batch identification, laboratory details, test specifications, results, and approval information. Its model illustrates documentation practice; referencing it does not mean a supplier or product has WHO certification.

Read each result against its specification

A specification is the acceptance criterion. A result is the finding for the tested sample. A “pass” statement should be supported by the relevant result and criterion. If the method, units, or criterion are absent, ask for clarification before treating the result as conclusive.

Also distinguish an identity test from an assay or a chromatographic purity result. They answer different questions. Read our guide to HPLC and LC-MS for that distinction.

What a COA does not establish

Only the listed tests are covered. Do not infer that a report includes sterility, endotoxins, residual solvents, or other properties unless those tests and findings are actually documented. A high purity number alone does not establish safety, clinical effectiveness, or permission for human use.

A COA also needs to be read in context: the material sampled, the method’s scope, and the documented handling of the sample. It is one part of a laboratory’s evaluation, rather than a substitute for the requirements of its own research protocol.

Questions to resolve before relying on a report

  • Does the batch match exactly?
  • Can the laboratory confirm the report’s authenticity?
  • Are methods, results, units, and limits stated?
  • Which required properties remain untested?

For questions about information displayed on this site, contact Astra Biolabs. See the research-use policy and return to the Research Library.

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