Storing and Handling Lyophilized Peptides in the Lab

You can buy the purest peptide available and still ruin it with poor storage. Peptides are sensitive to heat, moisture and repeated temperature swings, and how you handle them from the moment they arrive determines whether they last. Here is a practical overview for the lab.

On arrival

Lyophilized peptides tolerate short spells at ambient temperature — that is why they ship without cold packs — but they should not sit out. Move them into cold storage promptly. In their dry, freeze-dried state they are at their most stable.

Lyophilized (dry) storage

• Short term (days to a couple of weeks): refrigeration is generally sufficient.
• Long term: a freezer, ideally −20°C or colder, kept dark and dry.
• Keep moisture out. Let a vial reach room temperature before opening it, so atmospheric moisture does not condense onto cold powder.

Reconstituted (in-solution) storage

Once dissolved, stability drops sharply. Reconstituted peptide is normally refrigerated and used within a limited window. For anything beyond short-term use, aliquoting into single-use portions and freezing them is the standard approach — because the real enemy is the freeze–thaw cycle.

The freeze–thaw problem

Every time a solution freezes and thaws, a little more of the peptide degrades. Repeatedly freezing and thawing one vial is one of the most common ways good material goes to waste. Aliquoting means you only ever thaw what you need, once.

General good practice

• Label aliquots with compound, concentration and date
• Minimise light and air exposure
• Handle with clean, aseptic technique — see our reconstitution guide
• Follow any compound-specific guidance on the product page, which takes precedence over general rules

This article is laboratory reference material only and describes no use in humans or animals.