A Certificate of Analysis (COA) is the primary quality document for any research peptide.
It reports third-party test results for a specific production lot, so results always tie back to a lot number.
Purity (HPLC)
High-Performance Liquid Chromatography separates the peptide from related impurities and reports purity as a percentage of total peak area. For research work, look for 98% or higher.
Mass Verification
Mass spectrometry confirms the molecular weight matches the expected sequence, verifying identity.
Lot Traceability
Every COA is bound to a lot number. Matching the lot on your vial to the published COA is the single most important verification step.