---
title: "How to read a peptide certificate of analysis (COA)"
description: "A certificate of analysis lists lot-specific tests and results. The usual fields on a peptide COA and how they relate."
canonical: https://www.sablepeptides.co.uk/ref/certificate-of-analysis
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

# How to read a peptide certificate of analysis (COA)

## How to read a peptide certificate of analysis (COA)

*Last updated: 2026-10-10 · Research use only. Not for human or veterinary use.*

## Short answer

A certificate of analysis (COA) is a lot-specific document that lists the tests performed on a batch, the acceptance criteria and the results. For a synthetic peptide it typically covers appearance, identity by mass spectrometry, purity by HPLC and sometimes net peptide content, water, counter-ion and endotoxin. \[1\]

## At a glance

| Term | Definition / specification |
| --- | --- |
| Lot / batch number | Links the document to a specific vial run |
| Identity | MS observed mass vs theoretical |
| Purity | RP-HPLC area %, with chromatogram |
| Content (optional) | Net peptide content by AAA or nitrogen |
| Other (optional) | Water, counter-ion, endotoxin, appearance |
| Date and sign-off | Test date and responsible analyst or QA |

## Check the lot

A COA applies to one lot. Confirm the lot number matches the vial before relying on the figures.

## Look for raw data

A chromatogram and a mass spectrum let a reader check that the stated numbers follow from the data. Impurity profiling methods such as LC-MS are what generate these records.

## FAQ

**Is a COA the same for every lot?**

No. Each lot is tested and documented separately.

**Does Sable publish COAs on product pages?**

There is a CoA for every lot — request yours at /coa-request and we email it within 2 hours. See /education/what-a-documentation-request-is.

## Related reference pages

-   [What HPLC purity means for a research peptide](/ref/hplc-purity)
-   [Mass-spectrometry confirmation of peptide identity](/ref/mass-spectrometry-confirmation)
-   [Net peptide content vs gross weight](/ref/net-peptide-content)
-   [Reference index](/ref)

## Sources

1.  De Spiegeleer B et al. Impurity profiling quality control testing of synthetic peptides using liquid chromatography-photodiode array-fluorescence and liquid chromatography-electrospray ionization-mass spectrometry: the obestatin case. *Anal Biochem*. 2008. PMID: [18342612](https://pubmed.ncbi.nlm.nih.gov/18342612/)
2.  Verbeke F et al. Quality evaluation of synthetic quorum sensing peptides used in R&D. *J Pharm Anal*. 2015. PMID: [29403929](https://pubmed.ncbi.nlm.nih.gov/29403929/) · [PMC5762210](https://pmc.ncbi.nlm.nih.gov/articles/PMC5762210/)
3.  Choules MP et al. Quality Control of Therapeutic Peptides by (1)H NMR HiFSA Sequencing. *J Org Chem*. 2019. PMID: [30793905](https://pubmed.ncbi.nlm.nih.gov/30793905/) · [PMC6452441](https://pmc.ncbi.nlm.nih.gov/articles/PMC6452441/)

\---

Research use only. This page describes laboratory chemistry and analytical methods. It is not advice on any use in people or animals.

CoA for every lot — [request yours](/coa-request) and we email it within 2 hours.

Research use only. Not for human or veterinary use.

## Cite this

Research use only. Not for consumption. No health claims.

Plain

Sable Peptides. (2026). certificate-of-analysis. UK Research Peptide Reference. Retrieved 11 October 2026, from https://www.sablepeptides.co.uk/ref/certificate-of-analysis

APA

Sable Peptides. (2026, October 11). \*certificate-of-analysis\*. UK Research Peptide Reference. https://www.sablepeptides.co.uk/ref/certificate-of-analysis

BibTeX

@misc{sable\_certificate-of-analysis\_2026,
  author = {{Sable Peptides}},
  title = {{certificate-of-analysis}},
  year = {2026},
  howpublished = {\\url{https://www.sablepeptides.co.uk/ref/certificate-of-analysis}},
  note = {Accessed 11 October 2026. CC BY 4.0}
}

Badge

<a href="https://www.sablepeptides.co.uk/ref"><img src="https://www.sablepeptides.co.uk/badge/ref.svg" alt="Data: UK Research Peptide Reference — Sable Peptides" width="220" height="40"></a>

Date modified: 2026-10-16

Reviewed by Sable Peptides editorial team · 14 October 2026 · [Editorial policy](/editorial-policy)