Proper storage and reconstitution are essential for maintaining peptide integrity in research settings. Here’s a straightforward guide.

Why storage matters

Peptides are biological molecules that degrade when exposed to heat, moisture, light, and bacterial contamination. Incorrect storage can reduce purity, alter structure, and compromise research results. A few simple precautions go a long way.

Storing lyophilised (freeze-dried) peptides

Most research peptides are supplied in lyophilised form — a dry, stable powder. In this state, they’re relatively hardy, but still need proper care:

  • Short-term (up to 30 days): Refrigerate at 2-8°C
  • Long-term (1-12 months): Store at -20°C in a freezer
  • Extended storage (12+ months): Store at -80°C for maximum stability
  • Always: Keep in a sealed container away from direct sunlight and moisture
    Most researchers will be fine storing lyophilised peptides in a standard fridge or freezer.

Reconstituting peptides

Reconstitution is the process of dissolving the lyophilised powder into a liquid solution for research use. The standard solvent is bacteriostatic water (BAC water).

Step-by-step process

  1. Allow the peptide vial to reach room temperature — removing a cold vial and immediately adding liquid can cause condensation and degradation
  2. Draw up the appropriate volume of bacteriostatic water using a sterile syringe
  3. Inject the water slowly down the inside wall of the vial — never spray directly onto the powder, as this can damage the peptide
  4. Swirl gently to dissolve — do not shake vigorously, as this can denature the peptide
  5. Wait until fully dissolved — the solution should be clear with no visible particles

How much BAC water to use

The volume depends on your desired concentration. A common approach:

  • 2mL BAC water into a 10mg vial = 5mg/mL concentration
  • 1mL BAC water into a 5mg vial = 5mg/mL concentration
    Adjust based on your specific research requirements.

Storing reconstituted peptides

Once reconstituted, peptides are less stable than in lyophilised form:

  • Refrigerate at 2-8°C immediately after reconstitution
  • Use within 30 days for best results
  • Do not freeze reconstituted peptides — the freeze-thaw cycle can damage the molecular structure
  • Use sterile technique every time you draw from the vial to prevent bacterial contamination

What is bacteriostatic water?

Bacteriostatic water is sterile water containing 0.9% benzyl alcohol, which prevents bacterial growth. This makes it the preferred solvent for reconstituting peptides, as it allows for multiple draws from the same vial over time without contamination risk.
Eterna Labs stocks Bacteriostatic Water 10mL specifically for this purpose.

Common mistakes to avoid

  • Shaking the vial — always swirl gently
  • Using regular sterile water — it lacks the preservative needed for multi-use vials
  • Leaving reconstituted peptides at room temperature — refrigerate immediately
  • Freezing reconstituted peptides — stick to refrigeration only

– Using a contaminated syringe — always use fresh, sterile equipment

Eterna Labs supplies research-grade peptides and bacteriostatic water across New Zealand. Shop at eternlabs.co.nz/shop.

Research compounds mentioned