How to read a peptide certificate of analysis

A peptide certificate can contain several different kinds of information: product identifiers, analytical results, specifications and supplier statements. Reading them separately makes the document easier to understand.

This guide is a checklist for reviewing a certificate. For the difference between manufacturer documentation and independent laboratory reports, see batch testing and the source of the evidence.

1. Identify the document and the material

Record the issuing organisation, document reference, date, compound name and batch or sample identifier. Check whether the product is described with a particular sequence, modification or salt form.

A printed name, formula or CAS number identifies the intended material on paper. It is not a substitute for analytical evidence about the sample. Check that identifiers are consistent across the document and the supplied product information.

2. Separate results from specifications

A specification sets a requirement; a result reports what was measured or observed. A statement such as “at least 98%” may be an acceptance criterion rather than an individual measured value.

Record the wording used. If the document does not make the distinction clear, ask the supplier or issuer. Do not rewrite a specification as a precise batch result.

3. Read the analytical measurements

For mass spectrometry, locate the expected and observed mass information where supplied. The assessment should follow the method's stated criteria. There is no single mass tolerance that should be imposed on every peptide and instrument.

For HPLC, find the purity result, chromatogram and method information where available. Peak-area purity is a measurement under that method, not proof that all material in the container is the intended peptide.

For content, counterions and moisture, look for separate measurements and their units. Subtracting an assumed salt fraction from a nominal label quantity does not establish net peptide content. Bachem's analytical guide explains why these properties require distinct measurements.

4. Record what is absent

If content, sterility, endotoxin or stability information is not reported, mark it as not reported. Do not infer a pass from another measurement. Our purity, sterility and endotoxin guide explains the distinction.

Check the experimental requirements against the evidence available. A certificate should inform that assessment rather than replace it.

5. Resolve mismatches and keep the record

If identifiers disagree or a result is unclear, retain the document and ask a specific question: which sample was tested, how does it map to this lot, or which method produced this value? Record the explanation alongside the original report.

Keep the certificate version, batch reference and relevant correspondence with the experimental record. This preserves the reasoning behind the material review.

Using the HelixCore registry

The certificate registry distinguishes supplied manufacturer/source certificates from the separate supplier-report archive. The archive's Vanguard reports are not mapped to HelixCore inventory batches, and neither collection represents independent testing commissioned by HelixCore.

Use the document's own source description when recording it. For questions about the available documentation, contact HelixCore.