Guide
Peptide Storage & Stability
Storage rules for lyophilized and reconstituted research peptides: temperature, light, moisture, freeze-thaw and the degradation chemistry behind each rule.
Lyophilized material
A properly lyophilized peptide is a dry, amorphous cake with very little residual water, which is why sealed vials tolerate ambient transit. On arrival, store cool, dry and dark. For long-term storage, −20 °C in a desiccated environment is preferred; typical shelf life at that condition is 18–24 months.
Reconstituted material
Once dissolved, the peptide is in an aqueous environment and the clock starts. Hold at 2–8 °C, protect from light, and plan around a 28-day in-use window when bacteriostatic water is the diluent. If material must be frozen, aliquot first — repeated freeze-thaw cycles drive aggregation and measurable purity loss.
What actually degrades a peptide
| Mechanism | Trigger | Mitigation |
|---|---|---|
| Hydrolysis | Residual or absorbed moisture | Desiccated, sealed storage |
| Oxidation | Met/Cys/Trp residues, air, light | Amber vials, dark storage, minimal headspace exposure |
| Deamidation | Asn/Gln at elevated pH or temperature | Cold storage, appropriate diluent |
| Aggregation | Freeze-thaw, agitation | Aliquot; swirl, never shake |
| Adsorption | Dilute solutions on plastic surfaces | Appropriate labware, avoid over-dilution |
Visual checks
A collapsed or sticky cake suggests moisture ingress. Cloudiness, particulates or a colour shift after reconstitution suggests the material should not be used for measurement work.
Research use only. PX1 Research supplies compounds for laboratory and in-vitro research. Nothing on this page is medical advice, a dosing recommendation, or an offer for human or veterinary use.