Ask ten research peptide suppliers for a certificate of analysis and you will get ten different documents, several of which are a single number printed on a letterhead. The term is not standardised in this market, so it is worth being specific about what a useful analytical record actually contains.
Identity of the material
The document should state the compound name, the amino acid sequence in single- or three-letter code, the molecular formula and the calculated molecular weight. Sequence is the part most often omitted, and it is the part that makes every other number interpretable. A name alone is ambiguous: nomenclature in this field is inconsistent, and several compounds circulate under more than one name.
The analytical methods, not just their results
A purity figure without a method is an assertion. The record should state the technique — typically reverse-phase HPLC — along with the column, the mobile phase composition, the gradient, the flow rate and the detection wavelength. Those parameters are what make the number reproducible by someone else. Detection wavelength matters especially: 214 nm sees the peptide backbone, while 280 nm sees only aromatic residues, and a peptide with no aromatics can look far cleaner at 280 nm than it is.
Identity confirmation should be reported separately from purity, usually by mass spectrometry, comparing observed mass against calculated mass. Purity and identity are different questions and a single figure cannot answer both.
The chromatogram itself
A number extracted from a trace is a summary. The trace is the evidence. Baseline quality, peak symmetry, shoulders on the main peak and the behaviour of the gradient are all visible in the chromatogram and all invisible in the summary. A supplier willing to publish the image is making a stronger claim than one willing to publish only the percentage.
Quantitative content
Net peptide content belongs on the record, distinguished clearly from chromatographic purity, along with the counter-ion form and, where measured, water content. Without those figures a purchaser cannot calculate molarity correctly, and a purity figure alone will lead them to overestimate how much peptide the vial contains.
Provenance and traceability
The record should identify who performed the analysis and when. Independent third-party analysis carries more weight than in-house testing for the obvious reason that the analyst has no commercial interest in the outcome. The date matters because an analysis performed years earlier on different material is not evidence about what is in the vial in front of you.
What we do and do not issue — stated plainly
Our vials carry no batch or lot identifiers. A vial is matched to its published analysis by crimp and cap colour. We publish an independent reverse-phase HPLC analysis for each product on that product’s page, readable before you order rather than promised after it, and we do not issue per-vial certificates because we do not produce them.
We say that directly because the alternative is worse. A supplier who describes documentation they do not maintain has told you something about their record-keeping that no certificate can undo. If a supplier’s COA cannot be traced to the material in your hand by any mechanism at all, the document is decorative, and it is better to know which kind of document you are holding.
Using the record
Keep the analysis with your experimental notes, not just with the invoice. When a reviewer, a supervisor or a future version of you asks which material produced a particular result, the answer should be on paper. Record the compound, the supplier, the purchase date, the published analysis, the net peptide content and the counter-ion form. That set of fields survives an audit; a remembered impression does not.
Research use only. All products supplied by Battle Born Peptides are laboratory reference materials for in-vitro research and analytical use by qualified professionals. They are not drugs, foods, dietary supplements, cosmetics or medical devices; they are not approved by the FDA or any other regulator for use in humans or animals; and they are not intended to diagnose, treat, cure, mitigate or prevent any disease, or to affect the structure or any function of the body of humans or animals. Nothing in this article is preparation, handling or dosing guidance. See our full research-use terms.