Batch codes, records and traceability
Why the lot number on the vial is the most important thing printed on it, and what a usable record looks like.
Of everything printed on a vial label, the batch or lot code is the field that does the real work. The compound name tells you what it is meant to be. The lot code is what lets you prove it.
What a lot code connects to
A lot code identifies one specific production run. Behind it sits the manufacturing record, the purification conditions, the analytical results and the certificate issued for that run. Without the code, none of that can be matched to the vial in your hand.
This is why a certificate presented without a lot number is of no practical value. It may describe excellent material; it just cannot be shown to describe your material.
Checking a certificate against a vial
The check is quick and worth doing on arrival rather than six weeks later when a result looks strange:
- The lot code on the certificate matches the lot code on the label, character for character.
- The compound named on the certificate matches the compound named on the label.
- The certificate reports identity as well as purity, with the method stated for each.
- The issuing laboratory is named.
Keeping a usable record
A record that helps you later contains more than a purchase date. Worth capturing for each vial: compound, lot code, supplier, date received, storage location and conditions, date first opened, and — once reconstituted — solvent, concentration and date.
None of this is onerous, and all of it becomes valuable the moment an experiment produces something unexpected. The first question is always whether the material was what it was supposed to be, and the second is whether it was handled as it should have been. A record answers both; recollection does not.
Independent verification
Where a certificate comes from a third-party laboratory, that laboratory can usually be contacted directly to confirm the report is genuine. For our own batches, certificates are published against their lot codes and can be verified with the testing laboratory independently of us — which is the entire point of using one.