How to read a peptide certificate of analysis

Start with the material and batch

A certificate of analysis is useful when it can be connected to the material being offered. Before comparing headline results, match the product name, specification and batch identifier on the report to the quotation. A report for an earlier delivery does not establish the properties of a new batch.

• Match the material name and any stated salt or chemical form.
• Record the lot or batch number and report identifier.
• Check the issuer and analysis date.
• Ask whether the report covers the batch proposed for your order.

Read each test as a separate result

Identity, chromatographic purity and peptide content answer different questions. Mass spectrometry can support identity assessment, while HPLC is commonly used to assess chromatographic purity. A result should name its method, units and acceptance criteria where applicable.

Do not treat a purity percentage as a complete description of a material. Water, residual solvents and counterions may require separate measurements. A molecular illustration on a product page is a reference structure, not an analytical result for the supplied batch.

Reference: Bachem: quality control of amino acids and peptides

Ask for enough context to interpret the report

For your procurement file, keep the report with its related quotation and specification. Where your laboratory needs supporting chromatograms, spectra or method details, request those explicitly. A supplier-issued report and a report from an independent laboratory have different provenance; identify the issuer rather than assuming independence.

• Which tests were performed, and by whom?
• Are the underlying records available for review?
• Are results expressed as measured values or only pass/fail statements?
• What additional documentation does your institution require?

Request documentation with your quotation

At Holy Water, include the product, catalogue number, specification and required box quantity in your enquiry. Tell us which analytical records your organisation needs. Available batch documents can then be discussed alongside allocation and quotation review; document availability depends on the product and batch.

A quote request does not reserve inventory or confirm an order. Keep your organisation’s acceptance decision separate from the initial enquiry, and resolve any essential documentation questions before accepting supply.