How should I store my peptide when it is in lyophilizate?
For long-term storage the peptide should be kept in solid form in the deep freezer at < -20 °C. For short-time storage a refrigerator (2-8 °C) will suffice.
Peptides should be protected from intense sunlight.
Peptides containing fluorophores should be kept in the dark.
How long can I store peptides in solid form (as lyophilizate)?
The shelf stability of peptides is sequence-dependent. A few amino acids and partial sequences may react, even at low temperatures, e.g. Cys, Met, and Trp can be oxidized, -Asn-Gly- and -Asn-Ser- form aspartimide yielding further cleavage products.
Lyophilizates contain water, which may be involved in degradation reactions during storage. Peptides containing Asn, Gln, Cys, Met, Trp tend to be less stable. Moreover, the salt form affects stability.The stability may range from few months to years, if the peptide is kept in a tightly closeed vessel at <-20°C.
How should I store my peptide when it is in solution?
If storage of peptides in solution is absolutely unavoidable, use sterile buffers at pH 5-6 and store aliquots at -20℃ to prolong the storage life of peptides in solution.
How long can I store my peptide when it is in solution?
It is not recommended to keep excess peptides in solution. The shelf life of peptides in solution is very limited, especially for sequences containing cysteine, methionine, tryptophan, asparagine, glutamine, and N-terminal glutamic acid. In general, aliquot the necessary amounts of peptide for a few days and relyophilize remaining portions for long term storage if necessary.