This describes our own process, which makes it the one page on the site where we are the subject and not the method. It is written to the same standard we ask of a certificate: everything stated here can be checked, and the limits are set out as plainly as the capabilities.
The number on the label
Every vial carries a batch number in the format CDX-NNNN, for example CDX-1017, printed under the compound name. The same number appears on the certificate of analysis for that batch.
That matching pair is the whole mechanism. A certificate describes one batch, so a document whose number does not match your label describes different material, and everything on it is beside the point. It is the first check on our supplier checklist for exactly that reason, and the reason applies to us as much as to anyone.
Who runs the testing
An independent laboratory, commissioned and paid by us, covering purity by HPLC and identity by mass spectrometry on each batch. We do not test our own material and then report on it.
The distinction is worth stating because "tested" and "comes with testing" are different claims, and the distance between them is where a good deal of imprecise marketing in this category lives. Buying the analysis instead of inheriting it is what puts a batch number on the document in place of a specimen label.
Independence is the point of the arrangement. A certificate is a claim made by whoever issued it, so a laboratory with no stake in the sale is what separates the party making the claim from the party being paid for the product. A batch without that documentation does not get listed.
What the lookup does
Entering a number at the lookup confirms three things: that the number exists in our records, which compound and strength it corresponds to, and which analytical tests were run on that batch.
It is a traceability check. The underlying evidence is the certificate itself, which we send in full on request, including before you have ordered anything.
Three things the lookup does not do
It does not test your vial. No lookup can. It tells you what the records say about a batch; whether the powder in front of you is from that batch is a question only an analysis of that powder answers. This is true of every supplier's verification page, including ours.
It does not prove the material is unchanged. A certificate is dated because a result belongs to a moment. Peptides degrade by routes that proceed with time and temperature, and what happened between the analysis date and your bench is a matter of handling. (Reference: Manning et al., 2010) Our note on storage covers the routes.
It does not substitute for reading the certificate. A summary says tests were run. The document says what they found, under which method, on which date. Those are different amounts of information, and our guide to reading one goes field by field.
What the certificate should contain
The same fields we tell you to demand from anyone. Purity by RP-HPLC with its conditions, because the column and gradient change the number. Identity by mass spectrometry, with observed and theoretical mass shown instead of a verdict. A date. A named laboratory. The batch number.
Where a compound has a public record, there is an additional check available that does not involve us at all: take the formula from PubChem, calculate the mass with our calculator or any other, and compare it against the measured figure on the document. A seller who tells you to trust them instead of showing you how to check is asking for the wrong thing.
Why we publish the checks that could be used against us
The checklist and the CAS validator work on any supplier's paperwork, ours included. Generosity has nothing to do with it: that is the only version of this argument that holds together. A verification claim from a seller is worth what the buyer can confirm independently, so publishing the method is the claim.
It also sets a standard we then have to meet. If a document of ours fails a check on our own page, that is a real problem for us, which is the point of writing it down.
What a batch number is not
It is an identifier, not a grade. CDX-1017 says which production run a vial came from and nothing about how good that run was, in the same way a CAS number identifies a substance without describing a sample of it. Our note on CAS numbers makes the same distinction one level up.
Sequential numbering also carries no information about quality or age by itself. A lower number is an earlier batch, which is a fact about chronology. Whether an earlier batch is still at the figures on its certificate is a storage question, and the date on the document is what lets you ask it.
Where the number has to appear
Three places, and all three have to agree: the vial label, the certificate, and our records. Two out of three is not a pass. A label and a certificate that match each other but correspond to nothing in any record is the situation batch numbering exists to make visible, and it is why the lookup is a separate step and not a formality.
Our note on the documents that come with a batch sets out what each one establishes on its own.
If a number does not resolve
Check for typing first: the format is three letters, a hyphen and four digits. If it still does not come up, send a photograph of the label and we will trace it. A number absent from our records is not one of our batches, and we would rather know.
Research use only
All products sold by Codex Research are strictly for laboratory research and development. They are not for human or animal consumption and are not intended to diagnose, treat, cure, or prevent any disease.
Check this against a real batch
Every compound in the catalog lists its formula, molecular weight and CAS number, and every batch we ship has a certificate you can look up by number.
Frequently asked questions
What format is a Codex batch number?
CDX-NNNN, for example CDX-1017, printed on the vial label under the compound name. The same number appears on the certificate of analysis for that batch.
Who runs the testing on a Codex batch?
An independent laboratory we commission and pay, covering purity by HPLC and identity by mass spectrometry on each batch. We do not test our own material and then report on it.
What does the batch lookup confirm?
That the number exists in our records, which compound and strength it corresponds to, and which analytical tests were run on that batch. It is a traceability check; the evidence is the certificate itself.
Can I see the certificate before ordering?
Yes. Ask with a batch number, or with the compound name if you have not ordered yet, and we send the full document.
Does a successful lookup prove my vial is genuine?
It proves the number belongs to a real batch of ours and says what that batch was. Whether the powder in front of you came from that batch is a question only an analysis of that powder can answer, and that is true of every supplier verification page.
Why publish checks that could be used against Codex?
Because a verification claim from a seller is worth only what a buyer can confirm independently. Publishing the method is the claim, and it sets a standard we then have to meet.
References
- Manning, M.C., Chou, D.K., Murphy, B.M., Payne, R.W., & Katayama, D.S. (2010). Stability of protein pharmaceuticals: an update. Pharmaceutical Research, 27(4), 544-575.
- Dong, M.W. (2006). Modern HPLC for Practicing Scientists. Wiley.
- Fenn, J.B., Mann, M., Meng, C.K., Wong, S.F., & Whitehouse, C.M. (1989). Electrospray ionization for mass spectrometry of large biomolecules. Science, 246(4926), 64-71.
- Swartz, M.E., & Krull, I.S. (2012). Handbook of Analytical Validation. CRC Press.