Handling & Storage of Custom Peptides

All Sigma-Genosys peptides are supplied lyophilized and should be handled with the following considerations:

1. The peptide-containing vial should be tightly capped at all times. The experiment should be carefully planned to minimize opening of the peptide vial.
2. Short term storage(1 week to 2 months) of lyophilized peptide should be done in a freezer at -20⁰C. For longer storage, we recommend storing the peptide in a deep freezer at -80⁰C if available.
3. Repeated freeze-thaw cycles should be avoided for both lyophilized peptides and peptide solutions. If peptide samples need to be frequently or periodically taken from the stock, it is recommended to make a series of aliquots from the stock.
4. Peptide sequences containing C, M, or W are prone to air oxidation. It is recommended to purge the air out of the vial and replace it with a blanket of nitrogen or argon.
5. 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.