Storage and handling standards

Storage conditions

Conditions depend on physical state and intended holding period. The figures below are general laboratory practice for lyophilized peptides; compound-specific guidance on a product page takes precedence where the two differ.

Why freeze-thaw cycling matters

Each freeze-thaw cycle concentrates solutes at the ice interface and exposes the peptide to interfacial stress. Repeated cycling is the most commonly reported cause of potency loss in stored peptide solutions, and it is entirely avoidable by aliquoting into single-use volumes before the first freeze.

Aliquot volume should reflect the smallest routine experimental use, not the most convenient pipetting volume.

Handling practice

Handling errors cluster around three moments: opening a cold vial, adding diluent and mixing.

• Allow a vial to reach room temperature before opening to limit condensation onto the cake
• Add diluent slowly down the vial wall rather than directly onto the cake
• Swirl or roll to dissolve; avoid vigorous shaking, which shears peptide and creates foam
• Label aliquots with compound, lot, concentration, diluent and date
• Record the reconstitution scheme in your own bench records

Light, moisture and adsorption

Desiccation matters as much as temperature: a cold but humid environment can be worse than a cool dry one, because absorbed moisture reactivates hydrolytic pathways in the cake. Some peptides also adsorb to plastic surfaces at low concentration, which is a recognised source of apparent potency loss in dilute working solutions.