Peptide reconstitution & storage
A practical guide for researchers: how to correctly reconstitute a lyophilised peptide, at what concentrations, and how to store both dry powder and dissolved forms without losing activity. This guide is intended solely for laboratory research (Research Use Only).
1. Preparation
Allow the vial of lyophilised peptide to reach room temperature before opening. This prevents condensation on the inside of the vial that could affect the hygroscopic peptide. Work in a clean environment and swab the rubber stopper with an alcohol wipe before piercing.
2. Choice of solvent
Bacteriostatic water (0.9% benzyl alcohol in sterile water) is the standard for most research peptides. The benzyl alcohol provides bacteriostatic action and extends the usable life of the solution when refrigerated. Highly hydrophobic peptides may require a small amount of sterile acetic acid (0.1%) or DMSO to dissolve, then dilute to the target concentration with bacteriostatic water.
Every Europa Peptides vial ships with 3 ml bacteriostatic water included by default.
3. Step-by-step reconstitution
- Open both the peptide vial and the bacteriostatic water vial by removing the flip-cap, then swab the rubber stopper of both vials with an alcohol wipe.
- First draw an amount of air into the sterile syringe equal to the volume you want to take from the bacteriostatic water vial (for 1 ml of water, draw 1 ml of air).
- Insert the needle into the bacteriostatic water vial and inject that air. This equalises the pressure so you can draw the desired volume smoothly.
- Now draw the desired volume of bacteriostatic water (e.g. 1 ml).
- Insert the needle along the side of the peptide vial and allow the water to run down the wall slowly - not directly onto the powder.
- Wait 30–60 seconds and gently swirl the vial. Never shake - foaming can denature the peptide.
- Once the solution is fully clear, reconstitution is complete.
4. Concentration calculation
Concentration (mg/ml) = total peptide (mg) ÷ added volume of bacteriostatic water (ml). For insulin-syringe based dosing (IU) see our peptide calculator, which computes the required volume automatically.
5. Storage
Correct storage depends on the state of the peptide. Dry (lyophilised) powder can be stored for years at -20 to -80 °C in an airtight, opaque container. Reconstituted peptides are highly fragile and must be refrigerated at 2 to 8 °C, protected from light. Avoid repeated freeze/thaw cycles - aliquoting into smaller volumes reduces quality loss.
6. Common mistakes
- Shaking instead of gentle swirling
- Injecting water directly onto the powder
- Storing at room temperature after reconstitution
- Repeatedly freezing/thawing the same vial
- Exposure to light
- Non-sterile solvent or unclean workspace
Order research peptides
Europa Peptides supplies lyophilised research peptides at ≥ 99% purity, 3 ml bacteriostatic water included by default. Shipped from our Netherlands warehouse. Ordered before 16:00 on a business day = shipped the same day. For laboratory research only.