Storing lyophilized material
Keep unopened lyophilized vials cold, dry, and protected from light. A common research-bench practice is −20 °C storage for lyophilized peptides, with tighter control (−80 °C) when a protocol or certificate specifies it. Avoid repeated warm–cold cycling of the stock vial; condensation introduces moisture that accelerates degradation.
After opening, reseal promptly. Label the open date. Do not assume a powder that has sat warm on a bench for hours is still equivalent to a freshly received cold vial — document deviations when they happen.
Choosing a diluent
Reconstitution diluent should match the protocol: sterile water, bacteriostatic water (water with a preservative such as benzyl alcohol), dilute acetic acid, or another solvent specified by the method. Bacteriostatic water can help multi-use reconstituted stocks when the preservative is compatible with the assay; switch to preservative-free sterile water when the readout is known to be sensitive to benzyl alcohol.
Calculate volume from the vial’s labeled mass and the target stock concentration before you puncture the stopper. Add diluent slowly, allow the cake to wet, and swirl gently — aggressive foaming can denature some sequences and make concentration less reproducible.
Aliquots and freeze–thaw
Once reconstituted, portion working aliquots so the main stock is not thawed for every plate. Freeze aliquots promptly if the protocol calls for frozen storage of solutions. Minimize freeze–thaw cycles; many peptides lose integrity after repeated cycling even when the lyophilized solid was stable.
Protect aromatic-rich peptides from strong light during open-bench work. Record solvent, concentration, aliquot date, and lot number in the notebook so later anomalies can be traced.
What this page is not
This is laboratory handling guidance for research materials — not dosing instructions for humans or animals. Follow your institution’s chemical hygiene plan, PPE rules, and waste disposal procedures. For product-specific storage lines, see each product’s research details table; for diluent supply, see bacteriostatic water in the catalog.