A lot-documentation checklist for peptide procurement

Start with traceability, not a headline percentage

A useful evidence packet must connect the commercial item to the material tested. Record the exact product name, salt or formulation where relevant, strength, pack size, supplier SKU, and offered lot number. The same lot identifier should appear on the vial label, Certificate of Analysis, and any attached chromatogram or spectrum.

A generic specification sheet can explain intended targets, but it does not prove that a particular released lot met them. Before purchase, ask whether the available document is a lot-specific result or a reusable product template.

Review identity, purity, and quantity as separate questions

Identity testing asks whether the principal material matches the stated compound. Purity testing estimates the proportion of the target signal relative to detected impurities under the stated method. Quantity or content testing asks how much material is present. One result cannot silently substitute for the other two.

For every reported result, look for a named method, a specification or acceptance criterion, the measured result, units, and a clear pass or fail decision. If an attachment is part of the evidence, confirm its sample or lot reference matches the certificate.

A compact buyer checklist

The checklist below is deliberately short enough to use during quotation review. Additional tests may be appropriate for a particular material or research protocol, but missing traceability should be resolved before adding more analytical detail.

• Exact product, form, strength, pack, SKU, and offered lot are identified.
• The COA is lot-specific and names the methods actually completed.
• Identity, purity, and quantity or concentration are not conflated.
• Acceptance criteria, measured values, units, and disposition are visible.
• Chromatograms, spectra, or external reports reference the same lot or sample.
• Storage, retest or expiry information, and document revision are stated.