Lyophilised peptides arrive as a dry powder and must be reconstituted into solution before use in research. Done correctly, reconstitution is simple and preserves the integrity of the compound. This guide covers the technique, the choice of water, and storage.
What you need
- The lyophilised peptide vial.
- Bacteriostatic water (multi-use) or sterile water (single use).
- A sterile syringe and needle, and an alcohol swab.
Bacteriostatic vs sterile water
Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits microbial growth and allows multiple withdrawals from a vial over roughly 28 days when refrigerated. Sterile water has no preservative and is intended for single use. For most multi-withdrawal research, bacteriostatic water is the practical choice.
Step-by-step
- Swab the stoppers of both the peptide vial and the water vial.
- Draw your chosen volume of water into the syringe.
- Inject it slowly down the inside wall of the peptide vial — not directly onto the powder.
- Swirl gently until dissolved. Do not shake, as agitation can damage the peptide.
- Label with the date and store refrigerated.
Choosing your volume
The volume of water sets the concentration. For a 10mg vial, adding 2 mL gives 5 mg/mL; adding 1 mL gives 10 mg/mL. Choose a concentration that makes your measurements convenient and consistent.
Storage and stability
Keep reconstituted peptides refrigerated. With bacteriostatic water they are typically stable for around 28 days; with sterile water, use immediately. Always store the lyophilised vial cold and dry until you are ready to reconstitute. For ordering, see our how-to-buy guide.