Certificate of analysis (COA)
In short A document issued by a testing laboratory for one specific lot.
It states the substance, the lot number, the vial size, the date and method of analysis and, where measured, the purity. A certificate describes the lot that was tested, not the product in general.
Every certificate we hold is published in the certificate library and can be opened as a PDF without an account. The lot number printed on your vial label is the key that links the vial to its certificate.