The peptide solution is first frozen, then placed under vacuum. Frozen water turns directly from ice to vapour without going through a liquid stage. This is called sublimation.
How lyophilisation works
There are generally three main stages in lyophilisation:
Freezing: The peptide solution has to be frozen, and thus H₂O becomes frozen as ice.
Primary Drying: Caused by vacuum, it sublimates the ice, and only the frozen material stays in a gaseous state.
Secondary Drying: removing the water completely to have a dry stable product.
The outcome will give you a white powder or solid substance that may be stored or prepared for the research.
Why lyophilisation is used for peptides
Peptides may be sensitive to moisture, temperature and other environmental conditions. Easier to transport / handle. Removing water can help improve their stability in storage.
Lyophilised peptides also have a longer storage life under appropriate conditions than some peptide solutions. However, lyophilisation does not automatically make a peptide permanently stable. Storage temperature, container conditions, moisture exposure and the individual peptide all affect stability.
Lyophilised vs liquid peptides
A lyophilised peptide is supplied in dry form, while a peptide solution has already been dissolved in a liquid. Dry material can be useful when a peptide needs to be stored for longer periods before being prepared for a research experiment.
When a lyophilised peptide is reconstituted, the choice of solvent, concentration and handling conditions can affect the resulting solution. Some peptides may also require careful handling because they can be prone to aggregation or degradation after being dissolved.
How lyophilisation relates to peptide quality
Lyophilisation is a processing and storage method, not a test for peptide purity or identity. A freeze-dried product may require further analytical testing to confirm its quality.
The purity can be determined by HPLC, and the molecular mass can be confirmed by mass spectrometry (MS). A Certificate of Analysis (CoA) can tell you about purity, identity, appearance and other quality-control results.
When considering a lyophilised peptide for research, it is helpful to check the product information and CoA for details of peptide identity, purity, quantity and recommended storage conditions.
Related Terms: Freeze-Dried · Sublimate · Peptide Stability · Reconstitution · Aggregation · Degradation · HPLC · Mass Spectrometry · Certificate of Analysis
All products supplied by Prime Peptides UK are for laboratory research use only and not for human consumption.
Research Use Only. This glossary explains terminology used in published research. It is not medical advice and does not describe any product for human or animal use.