How to Properly Reconstitute Lyophilised Peptides

Lyophilised (freeze-dried) peptides are stable in powder form, but need to be reconstituted correctly before use in research. Getting this step wrong is one of the most common causes of inconsistent results.

Before You Start

Allow both the peptide vial and your chosen solvent (commonly bacteriostatic water) to reach room temperature before mixing. Combining cold solutions can cause visible cloudiness and may affect structural integrity.

Equalising Vial Pressure

The lyophilisation process can leave vials under vacuum or slight positive pressure. Using a sterile needle half-filled with air, gently equalise the pressure before withdrawing or injecting solvent — this reduces the risk of solution loss through the stopper.

Adding Solvent

Direct the needle towards the inside wall of the vial rather than directly onto the powder, and let the solvent run down gently. Swirl the vial to dissolve — avoid vigorous shaking, which can damage the peptide structure.

Volume Guidance

Using excessive solvent volume can increase the risk of fragmentation over time. As a general guide, 1–2.5ml is appropriate for most research applications unless a specific protocol calls for otherwise.

After Reconstitution

Store reconstituted peptides refrigerated (2–8°C) and use within the stability window appropriate to that compound. See our Reconstituting & Storage guide for more detail.

For laboratory research use only. Not intended for human use.