Lyophilization
Lyophilization is the freeze-drying process used to remove water from a peptide solution under vacuum at low temperatures. It preserves peptide structure and produces a stable powder for long-term storage.
Overview
The lyophilization process occurs in three stages: freezing the solution, primary drying (sublimation of ice under vacuum), and secondary drying (removal of bound moisture). Because the product never passes through a liquid water phase during drying, heat-sensitive molecules like peptides are preserved without denaturation. Commercial lyophilizers are large, expensive machines; peptide manufacturers use them to produce the vials sold to researchers. The resulting cake-like powder is then sealed in glass vials under inert gas to prevent moisture ingress. Understanding lyophilization helps explain why research peptide vials must be reconstituted and why peptides in solution have a much shorter shelf life than the dry powder.
Related Terms
Frequently asked questions
Is lyophilization the same as freeze-drying?+
Yes — lyophilization and freeze-drying are the same process. Lyophilization is the scientific term; freeze-drying is the common term.
Why is lyophilization preferred over simple drying for peptides?+
Conventional heat drying would degrade most peptides. Lyophilization removes water at low temperatures without the molecular damage caused by heat or oxidation.
Does lyophilization affect peptide purity?+
Done correctly, lyophilization preserves purity. Improperly done (e.g., incomplete drying or moisture ingress post-drying) can lead to aggregation or degradation over time.