The Definitive Guide to Peptide Storage

In peptide research, stability is everything. Using a degraded compound leads to unreliable data and inconsistent results. This guide covers the essential protocols for maintaining molecular integrity.

1. The Science of Temperature

Peptides are chains of amino acids held together by amide (peptide) bonds. High temperatures increase the kinetic energy within these molecules, causing them to vibrate more violently. This leads to hydrolysis, where water molecules break the amide bonds, cleaving the peptide into inactive fragments.

2. Lyophilized vs. Reconstituted

In its freeze-dried (lyophilized) state, a peptide is highly stable because water—the primary medium for degradation—is absent. Once you add a solvent (reconstitution), the clock starts ticking. The mobility of molecules in liquid form allows for chemical reactions like deamidation and oxidation to occur much faster.

3. Solvent Selection

Choosing the right solvent is critical. Bacteriostatic Water (BAC) contains 0.9% benzyl alcohol, which serves two purposes:

• Antimicrobial: It prevents the growth of bacteria that could consume the peptide or produce enzymes that degrade it.
• pH Buffering: It helps maintain a stable pH environment, which is crucial for molecular stability.

Using plain saline or sterile water typically increases the decay rate by 1.5x due to the lack of these protective properties.