What a Lot Number Is and Why It Matters

A lot, also called a batch, is a quantity of material made in one production run. Every vial from the same lot came from the same material, so a test on a sample from that lot describes all of it.

The lot number is the identifier given to that run. It appears on the certificate of analysis, and it should be recorded against your order.

It is the link between a vial and its lab report. A certificate for lot A says nothing about a vial from lot B, even if the product name is identical.

It makes problems traceable. If a lot is ever found to be wrong, the lot number is how a seller finds every order it went into.

It is how you check a seller's claims. Ask which lot you received and whether the published report is for that lot.

Stock is sent out oldest lot first, and every order records the lot each item was filled from. A lot that is quarantined or failed testing cannot be shipped; that is enforced by our system rather than left to memory.

Keep the lot number when you label a vial in your own lab. It is the only way to trace it back to its report later.