Research reference
Peptide Purity Testing & COAs Explained
A certificate of analysis (COA) documents the identity, purity, and quality of a peptide reference material using HPLC, mass spectrometry, and related analytical methods. The information below summarises publicly available laboratory characterisation data and is intended for qualified research professionals only.
What a peptide COA contains
A complete COA lists the peptide name and sequence, batch/lot number, manufacturing and test dates, HPLC purity percentage, mass-spectrometry identity confirmation, peptide content, water content, and acetate content where applicable.
HPLC purity
Reverse-phase HPLC is the industry standard for determining peptide purity. Research-grade material should test at ≥98% purity; premium suppliers target ≥99%.
Mass spectrometry
Mass-spec confirms the molecular weight matches the expected sequence, verifying identity. Nucleus Compounds provides mass-spec data with every COA.
Compliance notice
All references on this page describe laboratory research compounds intended strictly for in-vitro investigation by qualified researchers. Not for human consumption.
Frequently asked questions
What COA documents come with my order?
Every Nucleus Compounds order includes the batch-matched COA with HPLC purity and mass-spec identity confirmation.
What purity should I look for?
≥99% by HPLC is the premium standard for research reference materials.