Peptides should be stored in a dry, cool, dark place. For best preservation, store at 4°C or colder away from bright light. Dry peptides are stable at room temperature for days to weeks but for long-term storage -20°C is to be preferred (6). 

Contamination with moisture will greatly decrease the long-term stability of solid peptides. A vial containing a peptide should be allowed to warm to room temperature before being opened. After removing the desired quantity, the vial should be re-sealed, preferably under an atmosphere of dry inert gas, and then returned to cold storage (6). An ideal container for peptide manipulation should be clean, chemically inert, optically clear, strong, and available in an appropriate size. 

Glass and plastic vials are generally satisfactory for the purpose, however, care does need to be taken with plastic vials when organic solvents are to be used (6). Polypropylene vials are both strong and chemically inert but if high visibility is required glass is a better option. Please appreciate that peptide in solution can and do adsorb to many materials. This may occur to varying extents being dependent upon factors such as constituent amino acids, vial material, and peptide concentration. 

At high dilution, it is possible to lose large percentages of peptide due to adsorption to surfaces thereby grossly distorting subsequent results. The use of high-quality specialist glass and polypropylene vials can lessen this problem (6). The shelf life of peptide solutions is limited especially for peptides containing C, M, N, Q, and W. To prolong the storage life of peptides in solution, sterile buffers with a pH of around 5-6 should be used. Aliquots should be stored at -20°C or colder wherever possible. 

Avoid the use of frost-free freezers, which vary enormously in temperature during the frequent automatic defrosting cycles. Repeated freeze-thaw cycles are deleterious to peptides (6).