How to read a peptide certificate of analysis

Start with the batch

A certificate of analysis (COA) reports test results for a material. Start by matching the material name and batch or lot number to the item described by the supplier. An attractive certificate for a different batch does not answer the same question.

Read results against limits

FDA’s discussion of ICH Q7 describes certificates with the material name, grade, batch, release date, tests, acceptance limits and numerical results, as applicable. This pharmaceutical guidance is a useful reference for reading documentation; its citation does not mean a research supplier complies with it.

Ask what was actually tested

Write down the test, method, reported result and acceptance limit. If a result or method is missing, record it as missing rather than assuming it passed. A single reported purity value does not answer every quality question. Look for a separate result for any property being claimed.

Check the issuer and scope

Look for the laboratory or manufacturer, report identifier and date. Ask the issuer to confirm a report when a verification route is available. Keep a distinction between a supplier’s claim, a document supplied by that supplier and independently confirmed documentation.

What a COA does not establish

A COA is not a marketing authorisation, a clinical trial or a recommendation for personal use. It does not transfer findings from a medicine trial to a catalogue item. Use it to understand the documented material, not to infer a treatment outcome.

Primary sources

• FDA: COA information and ICH Q7
• FDA: ICH Q7 guidance