A certificate of analysis is the lot-specific test record for a batch of material. It is not marketing and not a generic product datasheet: it reports what was measured on one identified batch, by which method, on which date. A certificate that carries no lot number cannot be tied to the vial in hand and is effectively unverifiable.
What a complete COA contains
- Product name and full sequence, including modifications such as amidation
- Lot number, manufacture or test date, and quantity per vial
- HPLC purity as area percent, with the method and detection wavelength stated, plus the chromatogram
- Mass spectrometry identity: theoretical mass, observed mass, ionisation method
- Appearance, and where reported, water content, counter-ion or net peptide content
- The testing laboratory's name and signature
Why it matters
Two numbers do most of the work: identity confirms the right molecule, purity describes how much else came with it. Neither is meaningful in isolation, and neither transfers between lots. Independent third-party testing raises confidence because the party reporting the result is not the party selling the material.
Related terms
research use only. Read how to read a peptide COA and third-party testing explained.