COA + Testing

A COA is lot-specific

A useful certificate identifies the material, batch or lot, tests, methods or method references, acceptance criteria, numerical results, date and authorized issuer. A generic example does not establish the identity or quality of a purchased vial.

Identity, assay and impurities differ

Identity asks whether the expected substance is present. Assay estimates how much is present. Related-substance testing characterizes specified and unspecified impurities. One result cannot stand in for all three.

Sterility and endotoxin are separate

Purity does not demonstrate sterility, and neither demonstrates an acceptable endotoxin level. Method suitability, sample chain of custody and an accredited laboratory matter.

• Match the lot number to the container.
• Check report date and laboratory identity.
• Look for actual results, not only pass/fail language.
• Treat vendor-posted summaries as commercial claims until independently verified.