What "lyophilized" means for storage
Lyophilization (freeze-drying) removes water from a material under vacuum at low temperature, leaving a dry solid in a sealed vial. In that dry, sealed state, most peptide research materials are far more stable than they would be in solution, which is why they are supplied this way. The things that shorten that stability are the things that reintroduce water, heat, or light: a compromised seal, humid air, repeated warming and cooling, and direct light exposure.
Storage conditions commonly specified
| Factor | Common specification for sealed lyophilized material | Why it matters |
|---|---|---|
| Temperature | Refrigerated (2 to 8 °C) for shorter periods; frozen (around −20 °C) for longer-term storage, per the receiving laboratory's procedure. | Lower temperature slows chemical change in the dry solid. |
| Temperature cycling | Avoid repeated transitions between frozen and ambient conditions. | Each cycle can condense moisture on and around the container. |
| Light | Store in the dark or in an opaque container. | Some peptides are sensitive to light-driven degradation. |
| Moisture | Keep vials sealed until use and, where practical, in a desiccated container. | Water is the main driver of degradation for a freeze-dried solid. |
| Container integrity | Inspect the seal and stopper at receipt and before storage. | A compromised seal means the "dry, sealed" assumptions no longer hold. |
These are general conditions frequently cited for this class of material. They are not a guarantee of stability for any specific lot, and they do not override a receiving laboratory's own stability data or standard operating procedures.
Receiving and storage records
- On arrival, record the date, the material name, the labeled strength, the lot identifier, and the condition of each seal.
- Note the storage location and the temperature the location is controlled to.
- Match the lot to its published analytical record in the batch COA library and file the certificate number with the receiving entry.
- Log any excursion: a delivery left at ambient temperature, a freezer failure, a broken seal. The excursion is part of the lot's history.
When to set material aside
- The seal or stopper is damaged, or the vial shows visible moisture inside.
- The lot identifier on the vial does not match any received record.
- The container experienced an undocumented temperature excursion.
- The material's appearance differs markedly from other vials of the same lot.
Each of these is a reason to quarantine the container and record the observation, not a diagnosis. Disposition is the receiving laboratory's decision under its own procedures.