Peptide Storage & Reconstitution Best Practices

Maintaining peptide integrity from receipt through experimental use requires careful attention to storage conditions and reconstitution protocols. This guide covers established best practices used in research laboratories worldwide.

Storage Guidelines

• Lyophilized peptides: Store at -20°C or below in a dry environment. Most lyophilized peptides remain stable for 12+ months under these conditions.
• Reconstituted peptides: Store at 2-8°C for short-term use (1-2 weeks). For longer storage, aliquot and freeze at -20°C to avoid repeated freeze-thaw cycles.
• Light-sensitive peptides: Some peptides (particularly those containing tryptophan or methionine) are susceptible to photo-oxidation. Store in amber vials or wrap in foil.
• Humidity control: Lyophilized peptides are hygroscopic. Always allow vials to equilibrate to room temperature before opening to prevent moisture absorption.

Reconstitution Protocol

1. Allow the lyophilized peptide vial to reach room temperature (15-20 minutes).
2. Briefly centrifuge to collect all material at the bottom of the vial.
3. Add an appropriate volume of sterile bacteriostatic water or the specified solvent.
4. Gently swirl — do NOT vortex, as this can cause denaturation and aggregation.
5. Allow the solution to sit for 5-10 minutes if not fully dissolved.
6. Aliquot into sterile microcentrifuge tubes for single-use portions.

Common Solvents

• Bacteriostatic water (0.9% benzyl alcohol): Most common for general peptide reconstitution.
• Sterile water: For immediate single-use applications.
• DMSO: For hydrophobic or poorly soluble peptides (use minimal volume).
• Acetic acid (0.1%): For basic peptides with high isoelectric points.

Avoiding Degradation

The primary degradation pathways for peptides include oxidation, hydrolysis, aggregation, and deamidation. Minimize exposure to heat, light, oxygen, and pH extremes. Use nitrogen gas to displace oxygen in storage vials when possible.