How to Reconstitute Lyophilised Peptides: A Laboratory Guide

Reconstitution is the process of returning a lyophilised (freeze-dried) peptide to a liquid state before it can be used in a laboratory protocol. Done incorrectly, it's one of the most common sources of degraded or inconsistent research material — so getting the technique right matters as much as the quality of the peptide itself.

What You'll Need

• The lyophilised peptide vial, brought to room temperature before opening.
• Bacteriostatic water (0.9% benzyl alcohol preserved), for multi-use vials.
• A sterile syringe appropriate for the reconstitution volume.
• An alcohol swab to sterilise the vial stoppers.

General Technique

Sterilise both vial stoppers with an alcohol swab. Draw the required volume of bacteriostatic water into the syringe, then inject it slowly down the inside wall of the peptide vial rather than directly onto the powder — a fast, direct stream can damage the peptide's structure through excess agitation. Allow the vial to sit undisturbed, then gently swirl (do not shake) until the powder is fully dissolved.

Common Mistakes

The most frequent errors are: injecting the diluent too forcefully, shaking rather than swirling the vial, using plain sterile water instead of bacteriostatic water for a vial intended for multiple uses, and failing to bring the peptide to room temperature before reconstitution, which can cause a pressure differential and force liquid back out through the stopper.

After Reconstitution

Once reconstituted, refrigerate at 2–8°C and use within the timeframe set by your laboratory's standard protocol. See our guide to peptide storage and shelf life for more detail on stability after reconstitution.