Complete guide to peptide storage

## Why Storage is Critical

Peptides are sensitive molecules that can degrade if not stored properly. Degradation can occur through hydrolysis, oxidation, or aggregation, compromising biological activity and result reliability.

## Peptide Forms and Storage

### Lyophilized Peptides (Powder)

This is the most stable form for long-term storage:

- **Temperature**: -20°C or lower (ideally -80°C for very long storage) - **Light protection**: Keep in amber vials or wrapped in aluminum foil - **Humidity**: Dry environment, use desiccant if necessary - **Stability**: 1-2 years or more when stored correctly

### Peptides in Solution

Solutions are less stable than lyophilized powder:

- **Temperature**: -20°C for short term, -80°C for long term - **Aliquoting**: Divide into small aliquots to avoid freeze-thaw cycles - **Solvent**: Use sterile water, saline solution, or appropriate buffer - **Stability**: Weeks to months, depending on the peptide

## Good Storage Practices

### 1. Avoid Freeze-Thaw Cycles

Each cycle can cause degradation. Always aliquot the solution into small single-use volumes.

### 2. Minimize Air Exposure

Peptides containing methionine, cysteine, or tryptophan are particularly sensitive to oxidation. Use nitrogen or argon atmosphere when possible.

### 3. Protect from Light

UV light can cause degradation, especially in peptides containing tryptophan or tyrosine.

### 4. Keep Records

Document receipt date, reconstitution, number of uses, and observations about appearance.

## Peptide Reconstitution

### Recommended Solvents

- **Sterile water**: For most hydrophilic peptides - **Diluted acetic acid (0.1%)**: For basic peptides - **DMSO**: For hydrophobic peptides (use minimum concentration) - **Saline solution**: For neutral peptides

### Procedure

1. Allow the vial to reach room temperature before opening 2. Add solvent slowly along the vial walls 3. Swirl gently (do not vortex vigorously) 4. Check if completely dissolved 5. Aliquot immediately if not using everything

## Conclusion

Proper storage is as important as the initial peptide quality. Following these guidelines will ensure maximum shelf life and integrity of your reagents.