Storing peptides.

A freeze-dried peptide is stable, a dissolved peptide is not. That distinction determines everything that follows.

Before dissolving

Store sealed vials at minus 20 degrees, protected from light. In that state a peptide is stable for months. An ordinary freezer will do, an ultra-low freezer is not needed.

Brief transport at room temperature is no problem, as long as it stays brief. That is why we ship with dry ice and you store the vial straight after arrival.

After dissolving

As soon as water is added, breakdown begins. Keep the dissolved vial refrigerated, so in the fridge and not the freezer, and use it within the recommended period.

Use bacteriostatic water instead of plain sterile water. The benzyl alcohol in it inhibits bacterial growth, so a pierced vial stays usable longer.

Why not refreeze

With every freeze-thaw cycle, ice crystals form that mechanically damage the peptide chain. You hardly notice two or three cycles, ten you do. So avoid it after reconstitution.

Practical

• Freeze-dried: minus 20 degrees, dark, sealed.
• Dissolved: refrigerated, upright, not in the freezer door.
• Let the vial come to temperature before you pierce it, so no condensation gets in.
• Write the date of dissolving on the label.