Handling
Cold chain and temperature: a practical storage reference
· 5 min read
Cold chain gets discussed as if it were a single requirement. In practice a research peptide passes through several temperature regimes between synthesis and assay, and each has a different tolerance.
The temperature bands in practice
- Ambient — acceptable for sealed lyophilised powder in transit for short periods. This is why peptides ship without dry ice.
- 2-8 °C — refrigerated storage for reconstituted solutions in active use, and acceptable short-term storage for sealed powder.
- -20 °C — the standard long-term set point for sealed lyophilised material and frozen aliquots.
- -80 °C — useful for multi-year archival storage or unusually labile sequences; unnecessary for most catalogue compounds.
Shipping and transit excursions
Sealed lyophilised peptide tolerates ambient transit far better than most buyers expect, which is why international shipments arrive without refrigeration and are still fit for use. Degradation in the powder state at room temperature is slow.
A shipment delayed in a hot vehicle or left in direct sun is a different case. Record the condition on arrival, note any visible change to the powder, and if a consignment has clearly been mishandled, request analysis before committing it to a long experiment.
On receipt
- Inspect vials for cracked glass, lifted stoppers, loose caps and discoloured or clumped powder.
- Check the lot number on each vial against the certificate of analysis supplied.
- Move sealed vials to -20 °C promptly rather than leaving them on the bench overnight.
- Log receipt date and storage location against the lot number before the boxes are put away.
Managing freeze-thaw
Freeze-thaw cycling is the single most avoidable cause of potency loss. Aliquot reconstituted material into single-use volumes at the moment of reconstitution, while the concentration is known and the solution is fresh.
Label each aliquot with compound, concentration, lot and date. Thaw at 2-8 °C rather than in warm water, and never re-freeze a thawed aliquot.
Freezer discipline
- Avoid frost-free freezers — their defrost cycles deliberately raise temperature and are hostile to stored peptide.
- Store vials away from the door, where the temperature swings most.
- Keep material in a sealed secondary container with desiccant to limit moisture ingress.
- Log any freezer failure or extended door-open event against the affected lots.
Frequently asked
My shipment arrived at room temperature — is it ruined?
Usually not. Sealed lyophilised peptide is designed to travel at ambient temperature and short transit at room temperature is normal. Inspect the vials, check the powder, and store at -20 °C on receipt.
Is -80 °C better than -20 °C?
For most catalogue compounds -20 °C is sufficient and easier to maintain consistently. Reserve -80 °C for multi-year archival storage or sequences known to be unstable.
Research use only. All material referenced is supplied for in-vitro laboratory research by institutions and registered businesses. Not for human or veterinary use, and not for diagnostic or therapeutic purposes.