Manufacturer certificate vs. independent testing
Not every certificate of analysis carries the same weight. We explain what a manufacturer COA confirms, what it does not cover, and why a retest in an independent laboratory is stronger evidence.
Suppliers of research materials all point to certificates of analysis, but the same name covers two different documents with very different evidential weight. It is worth knowing the difference before you compare offers.
Manufacturer certificate
This is a document issued by the maker of the material for a specific batch. It describes the identity of the compound, its chromatographic purity, the method used and the date of analysis. It is the basic and, in practice, most commonly available proof of quality - every reputable batch should have one.
Its limitation is structural: the testing is performed by the same entity that produced and sells the material. That does not make the document worthless, but it is not independent confirmation.
Independent (third-party) testing
A retest means sending a sample from a specific batch to a laboratory with no connection to the manufacturer or the seller. The laboratory repeats the analysis using its own methods and issues its own certificate.
- it confirms the manufacturer's result through an independent measurement,
- it detects any discrepancy between the declaration and the actual state of the batch,
- with an accredited laboratory (e.g. ISO/IEC 17025) it comes with a documented quality system.
How we handle it
Every batch in our register has a manufacturer certificate of analysis. We publish the figures from it - method, purity and date of analysis - and send the document itself on request, since it comes from the maker of the material. Our own independent laboratory testing is in preparation; once it starts, results will appear as a second certificate alongside the same batch and will be clearly marked as such.
You will find the batch number on the label, on the invoice and in your order details - use it to look up the analytical data for exactly the material you received.
We supply these materials for laboratory research use only (RUO) - not for consumption by humans or animals and not for clinical applications. They are not a medicine, a medicinal product or a dietary supplement.