Cold-chain handling for lyophilized peptides

Peptides in solution are considerably less stable than peptides in solid form. Lyophilization (freeze-drying) removes water from the sample, slowing the hydrolysis and oxidation pathways that degrade peptide bonds and sensitive residues.

This is why research peptides ship as a dry powder or cake rather than as a ready solution, and why storage guidance changes the moment a vial is reconstituted.

Lyophilized material is generally stored at -20°C, protected from light and moisture. At this temperature, well-sealed material is typically stable over long periods.

Allow vials to reach room temperature before opening. Opening a cold vial in a humid room draws condensation onto the material, reintroducing exactly the water that lyophilization removed.

Once in solution, stability drops sharply and is measured in days to weeks rather than months. Refrigeration slows but does not stop degradation.

Repeated freeze-thaw cycling is a common source of unexplained variability between experiments. Aliquoting a reconstituted stock into single-use volumes avoids subjecting the whole sample to repeated cycles.

Lyophilized peptides tolerate short periods at ambient temperature during transit, which is why most research shipments do not require active cooling for intra-EU delivery times.

On arrival, transfer material to -20°C storage promptly rather than leaving it at room temperature on a bench.