Peptide Handling and Storage In general, peptide solutions are stable for up to a week at 4°C. However, if the peptide sequence has inherent instability (Peptide Stability), it might be better to freeze the solution when not in use. Peptide solutions at pH>8 should also be frozen when not in use. Sigma Aldrich.
Peptide Storage Information Great peptide storage information. Lerner. Peptides are provided as lyophilized product that should be stored as dry powder at -20°C to -70°C in a desiccator, if possible. After lyophilization, peptides retain significant amounts of water. Peptides are slowly degraded particularly the cysteine-containing peptides are oxidized over time at -20°C.