Correct storage is the single most important factor in maintaining peptide integrity between procurement and use. This protocol defines the minimum storage standards for research-grade synthetic peptide compounds.
Lyophilised Peptide Storage
Store at -20°C as a minimum. -80°C is preferred for long-term storage beyond 6 months.
Keep in original sealed vials until required.
Protect from light — UV exposure can cause photodegradation in certain amino acid residues.
Protect from moisture — silica gel desiccant packs should be present in storage containers.
Do not store at 2–8°C (refrigerator temperature) for extended periods — this is appropriate for short-term reconstituted solutions only.
Reconstituted Peptide Storage
Short-term (up to 7 days): store at 2–8°C in a sealed, light-protected vial.
Long-term: aliquot into single-use volumes and store at -80°C.
Avoid storing large volumes of reconstituted solution — each freeze-thaw cycle degrades compound integrity.
Freeze-Thaw Management
Repeated freeze-thaw cycling is the most common cause of peptide degradation in laboratory settings.
Follow these rules:
Prepare single-use aliquots before freezing — this eliminates the need to repeatedly thaw a single vial.
Never refreeze a thawed aliquot — discard after use.
Allow frozen aliquots to thaw at 2–8°C (not at room temperature) to minimise thermal stress.
Record the number of freeze-thaw cycles on the vial label where possible.
Degradation Indicators
Discard and do not use reconstituted solutions that show: visible particulate matter, cloudiness or turbidity, unexpected colour change, or an unusual odour. For lyophilised compounds, reject vials where the cake structure has collapsed, discoloured, or shows signs of moisture ingress.
Storage Temperature Reference
Lyophilised, long-term: -80°C
Lyophilised, standard: -20°C
Reconstituted, short-term: 2–8°C
Reconstituted, long-term aliquots: -80°C
