PEPTIDES PREFER THE COLD
It is recommended to store peptide vials refrigerated to help reduce peptide bond breakdown. When peptides are not yet reconstituted, many of them can last at room temperature, but it is still best to keep them in the refrigerator. Most peptides, especially shorter chain peptides, can be preserved for weeks in the refrigerator once reconstituted if one is careful.
[Optional] To keep the pressure equalized in a peptide vial, you can follow a few easy steps. First, fill the syringe with air equivalent to the amount of solution that you intend on drawing from the vial. For example, if you are going to draw 0.1mL of solution from the vial, first fill the syringe with 0.1mL of air and inject the air into the vial before drawing out the liquid solution.
If your syringe has air bubbles, turn it needle-side up, and lightly flick or tap the syringe so the tiny air bubbles collect at the top. Gently press the plunger on the syringe to push the air bubbles out until you see a drop or two of liquid escaping from the needle.
Be sure to use an alcohol wipe or rubbing alcohol to wipe the top of the vial before inserting a needle.
PROTECT PEPTIDES FROM LIGHT
In addition to storing peptides, both reconstituted and not, in the refrigerator, it is also highly recommended to store them away from direct sources of UV light. This is a second benefit of just keeping them in the refrigerator.
ONLY MIX WITH STERILE BACTERIOSTATIC WATER
The purity and sterility of bacteriostatic water are essential to prevent contamination and to preserve the shelf-life of dissolved peptides.
Buy high quality bacteriostatic water here.
Push the needle through the rubber stopper at a slight angle, so that you inject the bacteriostatic water toward the inside wall of the vial, not directly onto the powder.
Lyophilized peptides (not yet reconstituted) can be stored at -20°C (freezer) for longer shelf life, and the reconstituted peptide solution should be stored at 4°C (refrigerated). Do not freeze once reconstituted.
DO NOT SHAKE VIAL TO MIX
Air bubbles are unfavorable to the stability of proteins.