Peptides are fragile molecules. Even a high-purity product can degrade rapidly if handled, stored, or shipped incorrectly, undermining research reproducibility.
Lyophilized storage
Most peptides arrive as freeze-dried (lyophilized) powder, which is far more stable than liquid form. Store sealed vials refrigerated at 2–8°C and protected from light. For long-term storage of many months, freezing at −20°C extends shelf life; avoid repeated freeze-thaw cycles by aliquoting.
After reconstitution
- Use bacteriostatic water or the buffer specified in your protocol
- Refrigerate reconstituted peptide and use it within the recommended window, often 2–4 weeks
- Do not freeze reconstituted solution unless the vendor specifically supports it
Cold-chain shipping
Reputable suppliers ship lyophilized peptides in insulated packaging with cold packs, and many add temperature indicators. Lyophilized powder tolerates short periods at ambient temperature during transit, but prolonged heat exposure should be avoided. Inspect packaging on arrival and refrigerate immediately.
Signs of degradation
Clumping, discoloration, unusual odor, or results that fail to replicate across lots can indicate moisture exposure or degraded product. Document the lot number and contact the supplier with the CoA reference.
Following these practices protects the investment in every vial and, more importantly, the integrity of experimental data.