Laboratory guides
Peptide storage and solution stability
A storage condition is an instruction; stability is demonstrated for a particular material, state and period. One shelf life cannot be assigned to the whole catalog or automatically carried over after solution preparation.
Source editorial review:
Separate material states to avoid misleading dates
Keep separate records for the received container, stock solution and aliquots. Each state change introduces new information: vehicle, nominal concentration, container and handling. The original material date does not determine the usable period of those derivatives.
Stability can vary with sequence and chemical form. Oxidation and deamidation are different transformations; grouping them as “it went bad” is unhelpful when investigating a cause.
Case: the freezer raised an alarm
An alarm identifies an event; it does not by itself prove either loss or preservation of quality. Match affected containers to the temperature and duration record, check their instructions and seek an excursion assessment if no applicable criterion exists. Keep the pending decision visible.
A storage record another person can review
Alongside location, keep the source of the conditions and the review date. If a solution changes appearance, document the change before deciding on use. Do not “restart” its storage period by refreezing or transferring it.
A record for this decision
What supports a storage condition for this particular sample?
| Field | What to document |
|---|---|
| State | Distinguish solid, stock solution and working dilution. |
| Condition | Temperature, light, container and solution composition. |
| History | Receipt, openings, excursions and freeze–thaw cycles. |
When to leave the decision open
An unchanged appearance does not establish stability. Link the period of use to the applicable document or study and retain deviations for assessment.
Questions and answers
Do all peptides require the same temperature?
No. Consult conditions for the specific material and state; a supplier’s general recommendation does not replace stability data.
Does a normal appearance rule out degradation?
No. Some changes require analytical methods for detection. Visual inspection has limited scope.
Sources
- Bachem — Peptide handling and stability FAQs. Scope: Examples of sequence- and form-dependent stability. Conditions for each material require separate verification.
- WHO — Model guidance for storage and transport of time- and temperature-sensitive pharmaceutical products. Scope: Documentation framework for transport and temperature assessment. It does not assign pharmaceutical conditions to research reagents.