Research peptides are usually supplied lyophilized: freeze-dried into a dry powder or a small cake at the bottom of a sealed vial. In that state they keep far longer than in solution. How long depends on three things.
Temperature
Cold slows the slow chemistry that breaks peptide bonds and changes side chains. For storage longer than a few weeks, keep sealed vials at −20 °C. For a few weeks, 2–8 °C is generally acceptable. Avoid warming and cooling a vial again and again: every round can draw in moisture.
Moisture
Water is what lets degradation reactions run. A lyophilized peptide is hygroscopic, so it pulls moisture from the air the moment a cold vial is opened in a warm room. Let a vial come to room temperature, still sealed, before opening it, and close it again promptly.
Light
Some residues, tryptophan and tyrosine among them, react to light. Keep vials in their box or another dark container.
On arrival
- Check the seal is intact and the label's lot number matches the certificate.
- Put the vial in the freezer or fridge the same day.
- Record the date received beside the lot number.
Our shipping page covers how vials travel and what we do when one arrives damaged.
Sources
- Sigma-Aldrich, Handling and Storage Guidelines for Peptides (technical bulletin)
- Bachem, Care and Handling of Peptides (technical note)
Not medical or veterinary advice. For informational purposes only. Products we sell are for research use only and are not for human consumption.