Research guide
How to store lyophilised peptides
Research peptides are usually supplied as a lyophilised (freeze-dried) powder because they are far more stable dry than in solution. How they are stored after arrival still affects how long they keep. This guide summarises the handling advice published by major peptide manufacturers.
When a shipment arrives
Lyophilised (freeze-dried) peptides in sealed vials are generally stable at room temperature for short periods, which is why they are usually shipped without ice. Peptide manufacturers describe this stability in terms of days, not months.
For anything beyond short-term use, move vials into a freezer at -20 °C or colder, away from bright light. A refrigerator at around 4 °C is suitable only for short-term storage. Most lyophilised peptides stored this way remain stable for long periods, but stability depends on the sequence.
Keep moisture out
Lyophilised peptides are often hygroscopic: they absorb water from the air. Absorbed moisture lowers the peptide content by weight and can speed up degradation.
Before opening a cold vial, let it reach room temperature, ideally inside a desiccator. Opening a cold vial straight away draws condensation onto the powder. Open it briefly, work quickly and reseal it tightly.
Peptides rich in residues such as Asp, Glu, Lys, Arg or His are especially prone to taking up moisture and are best kept in a desiccator in a tightly capped vial.
Avoid repeated freeze-thaw cycles
Each freeze-thaw cycle can degrade a peptide. Plan how much is needed for each experiment and divide material into separate aliquots, so each portion is thawed once and the stock vial is not opened repeatedly.
Solutions are less stable than powder
Once dissolved, peptides are much less stable than in lyophilised form, and long-term storage in solution is not recommended. If a solution has to be kept, manufacturers advise dividing it into aliquots and freezing them at -20 °C or colder, using a slightly acidic buffer (around pH 5 to 6), and discarding any unused portion of a thawed aliquot.
Sequences containing Cys, Met or Trp are prone to oxidation, and those containing Asn or Gln also have a limited shelf life in solution. Limiting air exposure and using oxygen-free buffers helps with oxidation-prone sequences.
Check each product's storage information
Every peptide has its own stability profile. Each product page in our catalogue lists its form and recommended storage. Where a manufacturer certificate of analysis has been published, it is on our Batch documentation page.
Sources
This guide is general laboratory handling information. All Nautic Peptides products are supplied strictly for in-vitro laboratory research and are not for human or veterinary use.