Laboratory Storage Guide

Baseline storage principles

Peptide reference standards are sensitive to four principal stress factors: temperature, humidity, light and repeated freeze-thaw cycles. Effective storage practice controls each of these systematically rather than in isolation.

• Temperature: Cold storage slows chemical degradation. Lyophilised solids are typically held at −20 °C; long-term reconstituted stocks are also held at −20 °C in aliquots.
• Humidity: Water uptake accelerates hydrolysis. Lyophilised material should be kept desiccated and vials should be re-sealed promptly after opening.
• Light: Ultraviolet exposure can degrade aromatic residues. Store away from direct light where the peptide is known to be photosensitive.
• Mechanical stress: Avoid repeated freeze-thaw cycles and vortexing sensitive peptides; both can promote aggregation.

Storing lyophilised solids

1. Hold vials at −20 °C in a dedicated peptide-storage freezer where possible.
2. Keep desiccated: a sealed container or foil pouch with fresh desiccant is standard practice.
3. Equilibrate to room temperature before opening to prevent atmospheric moisture condensing onto cold material.
4. Record open date on the vial label; consider tracking cumulative time out of storage per SOP.

Storing reconstituted stocks

1. Immediately after reconstitution, aliquot into low-binding vials sized for single use where possible.
2. Label with peptide, concentration, diluent, date, batch and analyst.
3. Working aliquot in daily use: 2–8 °C.
4. Remaining aliquots: −20 °C, protected from light.
5. Thaw each aliquot only once; discard unused material per laboratory SOP.

Related procedures

• Laboratory Reconstitution Guide — from lyophilised solid to working stock.
• Retatrutide monograph — compound-specific storage detail.