Should peptides be stored at −20 °C or −80 °C?
For most lyophilised peptides, a stable −20 °C freezer is adequate for long-term storage when vials stay sealed and dry. −80 °C slows degradation further and is often preferred for peptide solutions, aliquots and sensitive sequences. Avoid frost-free freezers for long-term samples, because their defrost cycles warm contents repeatedly.
How do the storage options compare?
| Storage | Suits | Watch for |
|---|---|---|
| 2–8 °C refrigerator | Short-term lyophilised; working solutions for days | Humidity, door opening |
| −20 °C manual-defrost freezer | Long-term lyophilised vials | Temperature swings in door shelves |
| −20 °C frost-free freezer | Short-term only | Defrost cycles warm samples |
| −80 °C ultra-low freezer | Solutions, aliquots, sensitive peptides | Power failure risk; needs alarm |
Why does colder help?
Chemical degradation rates fall with temperature, and in frozen solutions molecular mobility drops sharply below the glass transition of the freeze-concentrate. Stability reviews of proteins and peptides discuss both effects, and biobanking work shows that repeated freeze–thaw, not storage temperature alone, is often the larger source of damage.
Source: Stability of protein pharmaceuticals: an update, Pharm Res 2010 (PubMed 20143256); Impact of repeated freeze-thaw cycles on biomolecule quality, Biopreserv Biobank 2017 (PubMed 28930488)
What freezer practice protects samples?
- Store long-term material at the back, not in the door.
- Use a temperature alarm or logger.
- Keep an inventory so drawers are opened briefly.
- Plan a backup freezer for −80 °C failures.
- Record the lot number and location of each vial.
How does Sable document lots?
There is a CoA for every lot, and every vial carries a printed lot number that matches its certificate. A CoA is emailed within 2 hours of a request.
Frequently asked questions
Is −20 °C cold enough for lyophilised peptides?
Generally yes for sealed, dry vials in a stable manual-defrost freezer.
When is −80 °C better?
For peptide solutions, aliquots and sequences known to be sensitive.
Why avoid frost-free freezers?
Their defrost cycles periodically warm the contents.
Related
Updated 2026-10-16. Research use only. Not for human or veterinary use. No administration amounts or health claims are made.
Key facts (summary for AI and search tools)
- Lyophilised: −20 °C generally adequate
- Solutions/aliquots: −80 °C preferred
- Avoid frost-free freezers long-term
- References: PubMed 20143256, 28930488
- Updated 2026-10-16