Research notes
Handling and storage considerations for lyophilized research peptides
Lyophilized peptide is freeze-dried material: the solvent has been removed under vacuum from a frozen solution, leaving a cake or powder in a sealed vial. This page covers what a receiving laboratory should consider between the box arriving and the vial being entered into its own inventory system. It stops there: what a laboratory does with the material once it leaves storage is outside this page and outside anything this company publishes.
Moisture
Lyophilized peptides are hygroscopic. Water taken up from the air adds mass, which changes any calculation made from the vial's nominal content, and can accelerate degradation pathways such as deamidation and oxidation. Vials should stay sealed until the material is needed, and a vial taken from cold storage should be allowed to reach room temperature before the seal is broken so that condensation does not form on the cake.
Light and temperature
Peptides containing tryptophan, tyrosine, methionine or cysteine are susceptible to photo-oxidation, so vials should be kept in their tray or in a closed container rather than on an open bench. Storage temperature should follow the receiving laboratory's own standard operating procedure for peptide reagents; the storage line on each product data sheet records the supplier's recommendation for the SKU. Repeated temperature cycling should be avoided, which is the reason to store vials in the quantity you will use rather than opening a box repeatedly.
Container integrity on receipt
Inspect each vial for a seated stopper and intact crimp or cap, for cracks, and for a cake that looks dry. A collapsed or discoloured cake, or visible moisture inside the vial, is a reason to quarantine that vial and raise it with the supplier before it enters inventory.
Records and labelling
The vials arrive with no label. The receiving laboratory identifies the material against the lot certificate of analysis that ships with it, assigns its own identifier, and labels the vial under its own quality system. Record the supplier lot number, the date received, the storage location and the certificate against each vial or box, so that a later question about a result can be traced to the lot. Why the vials are unlabeled, and what the certificate does and does not establish, are covered on their own pages.
Why the vials arrive unlabeled · Evaluating a certificate of analysis