What an inventory has to track

Peptide name, lot number, quantity, storage location, expiry date and current state. Lot number is what links each vial back to its certificate; state distinguishes an unopened lyophilised vial from a reconstituted one with an in-use clock running.

The expiry date is the field that repays the effort. Peptides expire quietly, and a vial found past its date during an experiment is a worse discovery than a vial flagged three weeks earlier.

• •Peptide name and lot number
• •Quantity and vial size
• •Storage location, specific enough to find it
• •Expiry or retest date
• •State: lyophilised, reconstituted, aliquoted
• •Date received and, where relevant, date reconstituted

First expiring, first used

Ordering use by expiry date rather than by arrival is what prevents material aging out. It is a small discipline and it is the one that most reduces waste in a freezer holding more than a handful of vials.

It requires the expiry dates to be visible, which is the whole argument for the record. Without it, the vial at the front of the box gets used and the one at the back expires.

Location precision

Freezer, shelf, box, position is the level of detail that lets someone retrieve a vial without leaving the door open. Every minute a freezer door is open, everything in it warms slightly.

This matters more than it sounds. A search through several boxes to find one vial exposes the whole freezer to a temperature excursion, which is exactly the thing the freezer exists to prevent.

Where the data lives

The inventory is stored in your browser's local storage, on this device. Nothing is transmitted, nothing is associated with an account, and no one else can see it.

The same properties make it fragile: clearing site data deletes it, private windows do not keep it, and it does not follow you to another device. For a record that has to survive, keep a durable copy elsewhere as well.

How the inventory and its alerts work

A local record per vial with derived expiry status, sorted so the items needing attention surface without being searched for.

days to expiry = expiry date - today

expired:  days < 0
critical: days <= 30
warning:  days <= 90
ok:       days > 90

1. 1Record each vial as it arrives. At the point of arrival, when the lot number and expiry date are on the packaging in front of you. Reconstructing them later is usually impossible.
2. 2Derive the expiry status. Days remaining against fixed thresholds, so a vial moves into warning and then critical without anyone reviewing the list.
3. 3Sort by urgency. Expired and near-expiry items first, so the list opens on what needs attention rather than on what happens to be alphabetically first.
4. 4Track state changes. Reconstituting a vial starts a second, usually much shorter clock. Recording the state and the reconstitution date is what makes that clock visible.
5. 5Keep it local. Everything is held in this browser. It is a working aid rather than a system of record, and it is not a backup.

What this method cannot tell you

• •Data is held in one browser on one device. Clearing site data deletes it and it does not sync anywhere.
• •It tracks what you enter. A vial not recorded is not tracked, and a wrong expiry date produces a confident wrong alert.
• •It does not know storage history. A vial stored warm has not had the shelf life its date describes.
• •It has no multi-user support and no audit trail, so it is not a regulated-environment record.

Where the numbers come from

• CDC injection safety guidance