Research Reference
Peptide Storage Guide
This reference describes the laboratory storage practices that preserve characterized purity of research peptides from delivery through the working window. All material is supplied strictly for in-vitro research and analytical reference.
Lyophilized (dry) peptide storage
Sealed lyophilized vials should be stored at −20 °C, protected from light and moisture. Most peptides are stable for 24+ months under these conditions. Before opening a cold vial, allow it to reach room temperature so atmospheric moisture does not condense onto the dry powder.
Reconstituted (in-solution) peptide storage
After reconstitution in bacteriostatic water (0.9% benzyl alcohol), store working solutions at 2–8 °C in a laboratory refrigerator. Most peptides are stable in solution for up to 4 weeks. Avoid storing reconstituted solutions at room temperature.
Freeze-thaw cycles
Repeated freeze-thaw cycles degrade most peptides via aggregation and oxidation. If a long hold of reconstituted material is required, prepare single-use aliquots before freezing rather than thawing and refreezing one tube. Frost-free freezers expose contents to repeated thermal cycling — they are not appropriate for long-term peptide storage.
Documentation and traceability
Each vial should be labeled — and the laboratory log should record — the lot number, reconstitution date, solvent and volume, concentration in mg/mL, and discard date. A peptide without a traceable label cannot support reproducible research.
Frequently Asked Questions
What temperature should lyophilized peptides be stored at?+
−20 °C or colder, sealed and protected from light, is the standard long-term storage condition for lyophilized research peptides.
How long are reconstituted peptides stable?+
Most reconstituted research peptides are stable for up to 4 weeks at 2–8 °C in bacteriostatic water. Sequence-specific stability data on the Certificate of Analysis takes precedence.
Can peptides be refrozen after thawing?+
Repeated freeze-thaw cycles degrade most peptides. The accepted practice is to prepare single-use aliquots before freezing so each tube is thawed only once.
Why warm a vial before opening it?+
Cold glass causes atmospheric moisture to condense on the dry powder when the seal is broken, accelerating hydrolysis and degradation.