Reconstituting and storing research peptides: a lab guide

Research peptides ship lyophilized (freeze-dried) because the dry powder is far more stable than a solution. How you reconstitute and store them determines whether that stability survives contact with your bench. This is a general laboratory-handling guide; it is not dosing guidance and these products are not for human or veterinary use.

Before you open the vial

Let the vial reach room temperature before opening. Opening a cold vial lets moisture condense onto the powder, which is exactly what lyophilization was protecting against. Work in a clean environment with sterile technique.

Reconstitution

• Use reconstitution water (0.9% benzyl alcohol) for multi-use reconstitution, or sterile water where a preservative is not wanted.
• Add the solvent slowly down the inside wall of the vial — don't spray it directly onto the powder or foam it.
• Let the peptide dissolve on its own; swirl gently. Do not shake vigorously.
• The solution should be clear. Persistent cloudiness or particulates warrant a closer look.

Calculating concentration

Concentration is simply peptide mass divided by solvent volume. For example, 10 mg of peptide in 2 mL of water gives 5 mg/mL. A reconstitution calculator makes it easy to convert between mass, volume and units drawn — our on-site calculator does exactly that for lab planning.

Storage

• Lyophilized (unopened): store at −20°C, protected from light and moisture, for long-term stability.
• Reconstituted: refrigerate at 2–8°C and use within the stability window appropriate to the peptide (often days to a few weeks).
• Avoid repeated freeze–thaw cycles of solutions; aliquot if you need long-term frozen storage of a reconstituted peptide.
• Keep vials upright and labeled with the reconstitution date.

Every Ascend Labs vial arrives with storage guidance and a batch number you can verify. If you're unsure about handling a specific compound, support can help.