Most research peptides are supplied as a lyophilised (freeze-dried) powder, which keeps them stable during shipping and storage. Before they can be used in laboratory work, the powder is dissolved into a liquid — a step known as reconstitution. Doing this carefully and consistently is essential for reproducible results.
What you need
- The lyophilised peptide vial
- A suitable solvent — most commonly bacteriostatic water (sterile water with 0.9% benzyl alcohol), which resists microbial growth over repeated access
- A sterile syringe and needle
- Alcohol wipes and a clean work surface
Choosing a solvent
Bacteriostatic water is the general-purpose choice for peptides that remain stable in solution for extended periods, because the benzyl alcohol preservative allows a multi-use vial to be accessed several times. Sterile or plain water may be preferred for single-use preparations or where a preservative could interfere with an assay. Some hydrophobic compounds require a small amount of a specialised solvent first; always check the compound’s documentation.
Step by step
- Allow the vial to reach room temperature and wipe both vial stoppers with an alcohol swab.
- Draw the chosen volume of solvent into the syringe.
- Insert the needle and let the solvent run slowly down the inside wall of the vial — never squirt it directly onto the peptide pellet, which can damage the peptide.
- Do not shake. Swirl gently, or leave the vial to stand, until the powder has fully dissolved into a clear solution.
- Label the vial with the compound, concentration and date.
Working out concentration
Concentration is simply the mass of peptide divided by the volume of solvent added. For example, a 5 mg vial reconstituted with 2 ml of bacteriostatic water gives 2.5 mg/ml (2500 mcg/ml). Choosing a round volume makes later measurement calculations far easier and reduces error.
Storage and stability
Lyophilised powder is best kept cold and dark; long-term storage is usually in a freezer. Once reconstituted, most peptides are kept refrigerated and used within a defined window — days to a few weeks depending on the compound. Avoid repeated freeze–thaw cycles of the reconstituted solution, as this degrades many peptides.
Quality starts with the raw material
Careful technique only matters if the starting material is what it claims to be. Every GenoPept compound is independently HPLC- and MS-verified and ships with a batch-specific Certificate of Analysis (COA), so you know the identity and purity of the peptide before you reconstitute it. Browse the full range in the research peptide store.
Related guides
Research use only. This article is general laboratory information and is intended strictly for qualified researchers handling materials for in-vitro and scientific research. GenoPept products are not for human or veterinary use.