Peptide Storage and Handling for Research Labs

Lyophilized storage

Sealed lyophilized vials are stable for months at refrigerator temperature and considerably longer frozen. For long-term storage, −20°C is the working standard and −80°C is used for archival material.

Keep vials in the dark and sealed. Freeze-dried powder is hygroscopic, and moisture absorbed from the air restarts the hydrolysis reactions that lyophilization was performed to stop.

Bringing a vial to room temperature

Always allow a cold vial to equilibrate to room temperature before opening. Opening a cold vial in humid air causes water to condense directly onto the powder — an invisible way to shorten a lot's usable life.

Reconstituted storage

Once in solution, refrigerate at 2–8°C and shield from light. Solution-state stability is compound-dependent and much shorter than the lyophilized shelf life, so validate a usable window rather than assuming one.

If longer solution storage is required, aliquot into single-use volumes and freeze. Repeated freeze–thaw cycling is one of the most damaging things you can do to a peptide solution.

• Lyophilized, long term: −20°C or colder, sealed, dark
• Lyophilized, short term: 2–8°C, sealed, dark
• Reconstituted: 2–8°C, dark, aliquot before freezing
• Always warm to room temperature before opening

Documentation

Record lot number, reconstitution date, diluent, concentration and storage location on the vial itself. Undocumented solution is unusable data.