A Certificate of Analysis (CoA) is the document that tells you what is actually in a vial. This UK guide explains what a peptide CoA shows and how to read one — essential for any researcher sourcing reference materials.
What a CoA is
A Certificate of Analysis is a batch-specific document produced from laboratory testing of the material. It confirms identity and reports purity, allowing a researcher to verify that a product meets specification before use.
Because it is batch-specific, a CoA reflects the actual material you receive rather than a generic claim about the product line.
HPLC purity
High-Performance Liquid Chromatography (HPLC) separates the components of a sample so that the main peptide can be quantified relative to any impurities. The reported purity percentage indicates how much of the sample is the target peptide.
Independent, third-party HPLC testing adds confidence because the analysis is performed outside the supplier.
Identity confirmation
Mass spectrometry is commonly used alongside HPLC to confirm identity by measuring the molecular weight of the peptide and checking it against the expected value for the stated sequence.
Together, purity and identity data give a complete picture: the right molecule, at a known level of purity.
Why it matters for reproducible research
Well-characterised materials are the foundation of reproducible research. A CoA provides the documentation trail that lets you trust your inputs and stand behind your results.
Every Stratum product is third-party HPLC tested with a Certificate of Analysis available on request. All products are for laboratory research use only.
Frequently asked questions
Do research peptides come with a Certificate of Analysis in the UK?
Reputable UK suppliers provide a batch-specific Certificate of Analysis (CoA) for each research peptide. Every Stratum peptide is third-party HPLC tested with a CoA available, shipped tracked across the UK for laboratory research use only.
What does a peptide CoA show?
A peptide CoA is a batch-specific document that confirms the identity of the peptide and reports its purity. It typically includes HPLC purity data and mass-spectrometry identity confirmation, so you can verify the material matches the label before use.
What is HPLC purity testing?
High-Performance Liquid Chromatography (HPLC) separates the components of a sample so the target peptide can be measured against any impurities. The reported purity percentage shows how much of the sample is the intended peptide; independent third-party testing adds confidence.
Is the CoA specific to my batch?
Yes. A Certificate of Analysis is batch-specific, so it reflects the actual material you receive rather than a generic claim about the product line.
This guide is for general educational purposes only and describes laboratory research practice. Stratum products are supplied for laboratory research use only — not for human or animal consumption. See our research use disclaimer.