A lot number is the only field in your records that cannot be reconstructed later. Quantities can be recounted, dates can be inferred from delivery notes, storage locations can be worked out from where the vial is now. But if nobody wrote down which production lot a particular piece of work used, that link is gone permanently, and with it goes the ability to say anything specific about the material behind a result. Lot tracking is not an administrative preference. It is the difference between a record that can be interrogated and one that can only be believed.
The lot is the primary key
Think of the lot identifier as the key that every other record joins on. The analytical document is lot-scoped. The inventory row is lot-scoped. The storage log entry, the aliquot label, the work record — all of them should carry the same string, and none of them should carry a paraphrase of it. Where a SKU code and a lot identifier both exist, they are not alternatives: the SKU says what the material is, the lot says which specific production run you are holding. The formal definition sits at lot number, and the wider concept at traceability.
The failure mode: two lots, one record
Here is how it actually goes wrong. A laboratory orders the same SKU twice. The first lot is documented carefully. The second arrives, goes onto the same shelf, and because the label looks identical at a glance, the existing inventory row is simply incremented. Now two production lots share one record, and any observation made afterwards cannot be attributed to either one. Nothing failed. No alarm sounded. The record is quietly worthless for the purpose it existed to serve.
The fix costs almost nothing: never increment a quantity across lots. A new lot is a new row, always, even when the SKU, the supplier, and the shelf are the same.
Where the chain usually breaks
In practice there are only a handful of breakage points, and they repeat across sites:
- A partially legible label transcribed from memory or from a photograph taken at an angle.
- An aliquot decanted into a secondary container labelled only with the compound name.
- A returned or unused vial put back on the shelf without its lot being re-checked.
- A spreadsheet column formatted as a number, silently stripping leading zeros from the identifier.
Each of these is trivially preventable and each of them is common. The spreadsheet one in particular has destroyed more identifiers than any handling error.
Aliquots and secondary containers
The moment material leaves its original container, the lot identifier stops travelling automatically and has to be carried deliberately. Any daughter container should show the parent lot, not just the compound name, and ideally the date of subdivision. A tube labelled with only a compound name is anonymous material — it might be correct, but nothing in your records can establish that. The vocabulary is at aliquot.
What to capture at receiving
Receiving is the one moment when the physical object and the paperwork are both in front of the same person, and it is therefore the cheapest place to establish the link. Capture the lot exactly as printed, the arrival condition, the intended storage unit, and whether a published record was found. Check the lot through the batch verification portal while the vial is still in hand, and file whatever you find. The portal walkthrough is at the batch verification guide, and the record-keeping chain is described at documentation traceability.
When a lot has to be held
Sometimes a lot needs to be set aside — a packaging anomaly, a label that cannot be read cleanly, a record that does not match. The important thing is that held material is physically separated and marked, not just flagged in a system. A vial that is questionable but sitting on the normal shelf will eventually be used by somebody who did not read the note. The practice is described at quarantine.
FAQ
What if the material arrives with no visible lot identifier?
Do not book it in. Contact support with the order reference and a clear photograph of the label before the vial is opened or shelved.
Can I use the order number instead of the lot?
No. An order can contain several lots, and a lot can appear across several orders. They answer different questions and neither substitutes for the other.
Does every lot have a published record?
Records are published where they have been uploaded for that specific lot. Record the outcome of your check either way, including when nothing was found.
How long should lot records be kept?
Longer than the material itself, since questions about a result arrive after the vial is gone. Set the retention period against your institution's policy. All material discussed here is supplied for in vitro laboratory research only.