Freeze drying preservation
Freeze drying is an effective method for preserving peptides. Making peptides into freeze-dried powder and storing them at -20 ℃ can maintain their stability for several years, avoiding bacterial degradation, secondary structure formation, oxidation, or other modifications. In addition, freeze-dried peptides can be stored for several years at -10 ℃ or lower without degradation.
Aseptic solvent dissolution
When dissolving peptides, it is recommended to use sterile water or distilled water and dissolve them under weakly acidic conditions, which can reduce the degradation of peptides by microorganisms, bacteria, and proteases. For peptides containing residues such as Met, Cys, Trp, etc., due to their susceptibility to oxidation, it is recommended to dissolve them in anaerobic solvents and obtain anaerobic water by injecting inert gases (such as nitrogen, helium, argon) under reduced pressure.
Packaging and preservation
To reduce the damage caused by repeated freeze-thaw cycles to peptides, it is recommended to pre package peptide samples in separate small bottles to avoid multiple freeze-thaw cycles.
Avoid humid environments
Peptides containing Asp, Glu, Lys, Arg, or His are prone to absorbing moisture from the air and being deliquescent, so these peptides should be stored in a sealed and dry container.
PH adjustment
Peptides have good stability under acidic conditions, and it is recommended that the pH range of the solvent be 3-6. It is best to package and freeze the dissolved peptides to avoid repeated freeze-thaw cycles.
Other precautions
For peptides containing Gln or Asn, their shelf life is relatively short due to their easy degradation.
If the peptide is highly hydrophobic due to the presence of aromatic side chains such as Val, Leu, Met, Phe, Tyr, Ala, or is a neutral peptide, the use of membrane denaturing agents such as DMF or DMSO can help dissolve the peptide.
In summary, in order to maintain the stability of peptides to the greatest extent possible, it is recommended to use freeze-drying storage method and sterile solvents during dissolution. Attention should be paid to adjusting the pH value and packaging storage, while avoiding humid environments and repeated freeze-thaw cycles.