We recommend storing lyophilized peptides in a dry container away from moisture and heat. Correctly stored, lyophilized peptides are stable at room temperature for several days, if not weeks.
If a longer storage time is desired, store peptides at -20° C.
Before use, warm up peptides to room temperature in a desiccator. This approach minimizes exposure of the peptides to moisture present in the air.
To avoid the degradation of peptides, use anhydrous nitrogen or argon to replace the air in the storage container. In between use, reaction vials and containers containing peptides can be sealed with parafilm and stored at -20°C.
Degradations reactions are possible in solution. However, the rate of degradation is sequence-dependent.
Possible degradation reactions in a peptide solution are
(i) the oxidation of cysteine (Cys, C), methionine (Met, M), and tryptophan (Trp, W),
(ii) deamidation of glutamine (Gln, Q) and asparagine (Asn, N) to glutamic acid (Glu, E) and aspartic acid (Asp, D), respectively,
(iii) and oxidative cyclization to form disulfide (Cys-Cys) bonds.