How to read a Certificate of Analysis (COA)
BioHackLab guide to interpreting identity, purity, analytical method, batch information and the limitations of a certificate of analysis.
A COA is a document, not a universal conclusion
A certificate of analysis should be tied to an identifiable sample and batch. The laboratory, date, methods and results should be traceable and interpreted in context.
HPLC and identity are not the same question
HPLC can describe chromatographic separation and purity within a method. Mass spectrometry can provide information about molecular mass and identity. They answer different questions and are complementary.
Purity does not tell the whole story
A high purity result does not automatically demonstrate exact quantity, sterility, endotoxin level or biological activity. These dimensions require separate tests and documentation.
What to verify in practice
Sample name, batch, method, reference standards, result, units, laboratory identification and the link between the document and the product are core traceability elements.