Reconstituting/Storage - Kensington Labs

Reconstitution and Storage of Peptides: A Complete Guide

Peptides — short chains of amino acids — play critical roles in biological functions and have valuable applications in research and medicine. To preserve their stability, efficacy, and safety, proper storage and reconstitution are essential.

This guide covers why correct handling matters, the best storage methods for both lyophilized and reconstituted peptides, realistic storage durations, and key tips for getting the best results.

Why Proper Storage Matters

Correct storage safeguards peptides in three key ways:

Stability – Peptides can degrade when exposed to heat, light, or moisture. Poor storage speeds up breakdown and reduces potency.
Efficacy – Preserving the peptide’s molecular structure ensures it retains its intended biological activity for accurate research or therapeutic results.
Safety – Degraded peptides can create harmful by-products, which may cause unreliable experimental results or adverse effects in clinical use.

Storing Lyophilized (Freeze-Dried) Peptides

Lyophilization — freeze-drying — removes water, leaving a dry, stable powder. To store lyophilized peptides:

Temperature – Keep at –20 °C or lower. For multi-year storage, –80 °C is best.
Containers – Use airtight, moisture-resistant vials.
Light Protection – Store in dark vials or wrap in foil to prevent UV degradation.
Avoid Freeze-Thaw Cycles – Repeated thawing damages peptide structure.

Storing Reconstituted (Mixed) Peptides

Reconstitution dissolves lyophilized powder in a suitable sterile solvent (e.g., bacteriostatic water, saline, or buffer). Once mixed:

Temperature – Store at 4 °C in the refrigerator for at least four weeks without significant degradation for most peptides.
For Longer Storage – Aliquot into sterile vials and freeze at –20 °C (months) or –80 °C (up to a year).
Containers – Use sterile, airtight vials.
Light Protection – Keep away from direct light, this can cause more damage to the peptide than the effects of temperature.

Recommended Storage Durations

Lyophilized Peptides

Short-Term (days–months) – Store at –20 °C
Long-Term (months–years) – Store at –80 °C

Reconstituted Peptides

Short-Term (up to 4 weeks) – Store at 4 °C
Medium-Term (1–6 months) – Aliquot and store at –20 °C
Long-Term (6+ months) – Aliquot and store at –80 °C

Best Practices for Reconstitution

Work Sterile – Use sterile tools and solvents to avoid contamination.
Choose the Right Solvent – Match the solvent to the peptide’s stability profile.
Mix Gently – Swirl lightly; avoid shaking to prevent damage.
Concentrate Stock Solutions – Higher concentrations reduce aggregation risk.
Aliquot Immediately – Split into single-use portions to prevent repeated freeze-thaw cycles.

Extra Tips for Maintaining Quality

Check pH – Use a solvent with a pH compatible with your peptide to prevent degradation.
Reconstitute Fresh Where Possible – Especially for sensitive peptides.
Label Clearly – Include peptide name, concentration, reconstitution date, and storage temperature.
Avoid Metal Contact – Use glass or plastic tools, not metal.
Watch for Precipitation – Cloudiness or particles may signal instability; filter if necessary.

Conclusion

By following proper storage and reconstitution procedures, you can preserve peptide potency, prevent degradation, and ensure reliable results.
For reconstituted peptides, four weeks refrigerated is a safe minimum before degradation becomes a concern — longer if frozen in aliquots. Always prioritize sterility, correct temperatures, and gentle handling to get the most out of your peptides.