Peptide storage 101: temperature, light, and shelf-life
Whether you're running a bench study or maintaining a small reference library, storage decisions materially affect peptide integrity. Here's a practical primer.
Peptide integrity is a function of three variables: temperature, moisture, and light exposure. Getting each right is straightforward once you understand what's actually degrading the molecule.
Lyophilized (dry) storage
In lyophilized form, most research peptides remain stable at -20°C for 24 months or longer. A standard laboratory freezer is sufficient. Avoid freeze-thaw cycles: every warm-up allows condensation to enter the vial and accelerate hydrolysis.
Reconstituted solutions
Once dissolved in bacteriostatic water, most peptides are stable for 2–4 weeks at 2–8°C (a standard laboratory refrigerator). Beyond that, gradual degradation via hydrolysis and oxidation begins to accumulate.
Light
Amber glass or opaque storage helps for a subset of peptides with tryptophan or cysteine residues, which are photolabile. When in doubt, store in the dark.
Practical checklist
- Keep lyophilized vials at -20°C until first use.
- Reconstitute with bacteriostatic (0.9% benzyl-alcohol) water.
- Label the reconstitution date on the cap.
- Refrigerate the reconstituted vial at 2–8°C.
- Discard after 30 days or if you see cloudiness or particulate.