Understanding Peptide Purity: How to Read a COA

A Certificate of Analysis (COA) is a quality document that accompanies every batch of a research peptide. It confirms the identity, purity and quality of the product.

Key COA parameters

Purity (>99%): HPLC purity indicates the percentage of the target peptide. Values above 99% are considered high purity.

Molecular weight: Mass spectrometry (MS) confirms the correct molecular weight of the peptide.

Retention time: HPLC chromatography shows the retention time and confirms identity by comparison with a reference standard.

What to look for

A complete COA contains: batch number, analysis date, test method (HPLC/MS), purity grade, molecular weight and signature of the responsible person.

PrimePeptides provides batch-specific COAs for every product, accessible on the product page.