Key Takeaways: Quick Reference Matrix
| State | Storage Condition | Estimated Shelf Life |
|---|---|---|
| Lyophilized (Powder) | Freezer (-20°C) | 24 – 36 Months |
| Lyophilized (Powder) | Room Temp (Away from light) | 30 – 90 Days (Stable) |
| Reconstituted (Liquid) | Refrigerator (2-8°C) | 14 – 30 Days (Depends on Peptide) |
| Reconstituted (Liquid) | Freezer | NOT RECOMMENDED (Damages structure) |
Proper storage is the single most critical factor in maintaining the purity and efficacy of research peptides. Unlike stable organic compounds, peptides are fragile amino acid chains prone to degradation via hydrolysis and oxidation. This guide outlines the laboratory standards for handling lyophilized and reconstituted peptides.
1. Handling Lyophilized Peptides
Most research peptides arrive in a lyophilized (freeze-dried) state. This process removes water to ensure stability during transport. Upon receipt, the vials should be stored immediately in a freezer at -20°C if not intended for immediate use.
Critical Step: Before opening a vial that has been stored in the freezer, allow it to reach room temperature naturally (approx. 20-30 minutes). Opening a cold vial introduces condensation (moisture) from the air, which can prematurely degrade the peptide.
2. The Reconstitution Protocol
Reconstitution requires a bacteriostatic solvent to prevent bacterial growth. The standard in research settings is Bacteriostatic Water (0.9% Benzyl Alcohol).
- Step 1: Swab the stopper with an alcohol pad.
- Step 2: Slowly inject the bacteriostatic water down the side of the glass vial. Do not inject directly onto the powder “puck” to avoid damaging the peptide bonds.
- Step 3: Gently swirl the vial. Never shake a peptide vial. Shaking creates micro-bubbles and shear stress that can denature the amino acid chain.
3. Storage of Reconstituted Peptides
Once mixed with a solvent, the “clock starts ticking.” Reconstituted peptides must be kept refrigerated at 2°C to 8°C. They should never be refrozen, as the freeze-thaw cycle of water crystals will destroy the molecular structure.
Summary of Degradation Factors
Researchers must protect peptides from three primary enemies:
- Light (UV Radiation): Breaks down chemical bonds. Always store in dark areas.
- Heat: Accelerates chemical reactions and bacterial growth.
- Agitation: Physical stress breaks fragile peptide chains.
