A certificate of analysis describes a lot on the day it was tested. Whether it still describes that lot six months later depends on what happens after delivery. Most degradation in the lab comes down to three things: heat, light and moisture — plus the occasional container left open for "just a minute".
This guide covers practical storage habits that protect solid research compounds and keep every lot traceable.
The three enemies of a stable sample
1. Heat
Chemical reactions — including the slow ones that degrade a compound — speed up as temperature rises. Keep stock in a cool, stable place, away from radiators, windows, ovens and the top shelves of a warm room. Temperature swings are as unwelcome as high temperatures: they drive condensation inside containers.
2. Light
UV and visible light can trigger photochemical reactions, especially in molecules with aromatic rings or conjugated systems. Store compounds in their original, closed container, inside a cabinet or drawer rather than on an open bench.
3. Moisture
Water is the most common problem for solids. It can cause clumping, hydrolysis of esters and amides, and makes weighed masses inaccurate. Peptides are often hygroscopic, and residues such as methionine are also prone to oxidation — one reason peptide material like Adamax should stay dry and sealed.
- Keep containers tightly closed and open them only for as long as needed.
- Let refrigerated containers reach room temperature before opening, so moisture doesn't condense on the cold material.
- Store sensitive material with a desiccant in a secondary container.
Synthetic semax-derived peptide
Refrigerated or room temperature?
| Situation | Usual approach |
|---|---|
| Label states a temperature | Follow the label — it overrides everything here |
| Solid material, used regularly | Cool, dry, dark cabinet; avoid frequent temperature changes |
| Solid material, longer-term reserve | Refrigerated, sealed, with desiccant, if the label allows |
| Solutions | Prepare fresh where possible; aliquot to avoid repeated freeze–thaw cycles |
Keep every lot traceable
Good storage includes good records. A sample you can't trace back to its lot and CoA is a sample you can't fully trust in a write-up.
- Write the date received and the date first opened on the container.
- Record the lot number, storage location and conditions in your lab notebook or inventory system.
- File the CoA with the lot number — see our guide on how to read a certificate of analysis.
- Use the oldest lot first, and retire material that looks different from its description on the CoA (colour change, clumping, odour).
Order only what you need
The simplest way to keep material fresh is not to keep too much of it. Pre-weighed units help here: each unit stays sealed until the moment it is used, so the rest of the lot isn't exposed every time you open the container.
Pre-weighed units, sealed until you need them
Full specifications and the HPLC purity of the current batch on every listing.