Storing Lyophilized Peptides in the Lab

Almost every peptide in our catalog arrives as a lyophilized — freeze-dried — powder rather than a solution, and that choice is about chemistry, not convenience. In solution, peptides hydrolyze, oxidize, aggregate, and adsorb to container walls. Remove the water and every one of those degradation routes slows dramatically: a properly stored lyophilized peptide is typically stable for years, which is also why room-temperature transit during shipping is not a stability event.

Moisture is the main threat. Lyophilized cakes are hygroscopic — they pull water from the air — and absorbed moisture restarts hydrolysis. This is the reason for the classic lab rule: when a vial comes out of the freezer, let it warm fully to room temperature before opening, so humid air doesn't condense onto the cold powder.

Temperature drives every degradation reaction faster. Standard practice for long-term storage of lyophilized peptides is −20 °C or below; short holding at 2–8 °C is acceptable for material in active use.

Light, especially UV, damages tryptophan-, tyrosine- and methionine-containing sequences — hence amber vials and dark storage.

Freeze–thaw cycling matters mainly for solutions. Repeated freezing and thawing shears and aggregates dissolved peptides, which is why laboratories aliquot dissolved material once rather than refreezing it repeatedly.

Received vials go into a −20 °C freezer, dark and dry, ideally with desiccant. Before opening, equilibrate to room temperature. Aqueous solutions of peptides are less stable than the lyophilized solid; prepare them only as needed for the assay and follow your laboratory's stability data. The storage condition for each product is listed in its specifications table.

Temperature-sensitive items ship with cold packs — see the FAQ for shipping specifics.