The Certificate of Analysis (CoA) is one of the most valuable documents in the lab. It records the results of the tests performed and ties them to a specific batch. A CoA proves precisely what it states, and nothing beyond that, and that very boundedness is what makes it useful. This page explains what the Peptalis CoA contains, when it is issued, and how it reaches you with an order.
What the Peptalis CoA contains
A complete CoA for a synthetic peptide has a fixed core. It states the identity of the substance and the measured molecular mass, usually confirmed by mass spectrometry. It gives the chromatographic purity, most often by HPLC, with the method noted. It reports a content determination, or notes its absence. It records the appearance of the material, the batch or lot number, the production or test date, and, where determined, the water content and residual solvents.
What sets the Peptalis CoA apart from bare lab data is the second layer: the own verification. The document brings the analytical lab testing and the Peptalis verification layer together, on its own letterhead, signed by Peptalis Quality, the only signatory in the public documentation, never an individual name. What Peptalis has established itself is stated as such; what could not be established itself is named rather than left out.
When it is issued
The CoA is the closing step of the Peptalis standard, not the starting point. Every batch passes through three steps. First the analytical lab testing by the producing laboratory, with methods such as identity by mass spectrometry and purity by HPLC; the methods used are listed on the batch report. Then an internal assessment following a fixed procedure: checks on identity, purity and stability, visual inspection and vial integrity, and where relevant a reconstitution test. Only when those steps hold does Peptalis issue its own CoA.
That order is why the CoA means something. It is not filled in beforehand and it does not follow a batch still to be assessed; it confirms a batch that has passed the assessment. Where Peptalis sees reason to, a batch can additionally be tested at an independent European laboratory; that report is an internal control instrument and not part of the public certificate. A batch that does not meet the standard is rejected and receives no CoA, because then there is nothing to certify.
What a CoA does not prove
The boundary of a CoA lies at what was not tested. A certificate that reports purity and identity says nothing about sterility unless a sterility test was performed and stated, and nothing about endotoxins if no such test appears on it. A purity percentage, moreover, shows only the impurities the method makes visible. The core rule is simple: a CoA is evidence of the tests performed, not of the absence of everything that was not tested. Absence of an entry is not evidence of absence of the problem, and Peptalis prefers to show that distinction rather than hide it.
How you receive it
The CoA does not come detached from the vial. At Peptalis, every order ships as standard with the own Peptalis CoA (the release report), in Dutch or English according to the order, the batch number and the storage conditions. The analytical lab testing behind the release stays an internal source and does not travel with the order. The batch number on the certificate reappears on the vial label, so that certificate and material belong together unambiguously. Entering a batch code in the batch lookup also opens the corresponding release report directly, convenient to share or retrieve without digging up the order confirmation.
A certificate without a traceable batch number or date loses exactly the link that makes it useful. That is why the way the CoA is delivered, tied to the vial and to the batch, matters as much as what it states.