Peptide Storage Guide
Proper storage protocols for maintaining peptide integrity from delivery through experimentation.
Temperature Requirements
| Form | Temperature | Typical Stability |
|---|---|---|
| Lyophilized powder | -20°C (freezer) | 2+ years |
| Lyophilized powder | 2-8°C (refrigerator) | 6-12 months |
| Reconstituted solution | 2-8°C (refrigerator) | 2-4 weeks |
| Reconstituted solution | -20°C (frozen) | 3-6 months |
Lyophilized Powder Storage
Lyophilized (freeze-dried) peptides offer maximum stability because water — the primary driver of chemical degradation — has been removed. Follow these rules:
- Store at -20°C for long-term preservation (2+ years)
- Keep vials sealed until ready for reconstitution
- Protect from light — UV radiation degrades peptide bonds
- Avoid humidity — lyophilized powders are hygroscopic and absorb moisture from air
- Only open vials in low-humidity environments
Reconstituted Solution Storage
Once dissolved in bacteriostatic water, peptide stability decreases significantly. The addition of water enables hydrolysis and microbial growth.
- Use bacteriostatic water (0.9% benzyl alcohol) — not plain sterile water
- Store refrigerated at 2-8°C and use within 2-4 weeks
- Aliquot into single-use vials to avoid repeated freeze-thaw cycles
- Do not shake vigorously — causes aggregation and denaturation
- Store in dark, airtight containers
Common Storage Mistakes
Room temperature storage
Even short-term room temperature exposure accelerates degradation. Always refrigerate or freeze.
Repeated freeze-thaw cycles
Each cycle causes aggregation. Aliquot into single-use portions before freezing.
Exposure to air
Oxygen degrades sulfur-containing peptides (oxidation). Minimize headspace in vials.
Wrong pH buffer
Extreme pH accelerates hydrolysis. Use recommended buffers for your specific peptide.
Using plain water
Bacteriostatic water prevents microbial growth. Plain sterile water does not.
Stability Warning Signs
Discard any peptide solution that shows these signs of degradation:
Cloudiness or precipitation in solution
Color change (yellowing or browning)
Visible particulate matter
Loss of characteristic solubility
Unusual odor