Complete Guide to Peptide Reconstitution

Proper reconstitution of lyophilized peptides is essential for maintaining compound integrity and ensuring accurate dosing in research protocols. This guide provides detailed instructions for safely and effectively reconstituting peptides for laboratory use.

Required Materials

• Lyophilized peptide vial
• Bacteriostatic water (0.9% benzyl alcohol) or sterile water
• Alcohol swabs (70% isopropyl alcohol)
• Sterile syringes (1-3mL) with needles (typically 25-30 gauge)
• Sterile gloves
• Clean work surface or laminar flow hood

Step-by-Step Reconstitution Process

Step 1: Preparation

Remove the peptide vial from freezer storage and allow it to reach room temperature (approximately 15-30 minutes). This prevents moisture condensation on the peptide when opening the vial. Clean your work surface and put on sterile gloves.

Step 2: Calculate Reconstitution Volume

Determine the desired concentration based on your research protocol. For example, to create a 2mg/mL solution from a 10mg peptide vial, you would add 5mL of solvent. Use this formula: Volume (mL) = Peptide Amount (mg) / Desired Concentration (mg/mL).

Step 3: Clean Vial Tops

Wipe the rubber stopper of both the peptide vial and bacteriostatic water vial with an alcohol swab. Allow to dry completely (approximately 30 seconds).

Step 4: Draw Solvent

Using a sterile syringe, draw up the calculated volume of bacteriostatic water. Inject air into the bacteriostatic water vial first (equal to the volume you wish to withdraw) to equalize pressure.

Step 5: Add Solvent to Peptide Vial

Insert the needle into the peptide vial at a 45-degree angle, aiming the stream of liquid against the inside wall of the vial. Add the solvent slowly, allowing it to run down the side of the vial onto the peptide cake. Do NOT inject directly onto the peptide as this can damage it.

Step 6: Allow to Dissolve

Let the vial sit undisturbed for several minutes to allow the peptide to dissolve. Most peptides will dissolve within 5-10 minutes. If the peptide is not fully dissolved, gently roll the vial between your palms. Never shake vigorously as this can denature the peptide.

Troubleshooting

If the peptide does not dissolve completely in aqueous solution:

• Allow more time (some peptides require 30+ minutes)
• Try gentle warming to room temperature if refrigerated
• For hydrophobic peptides, add a small amount (10-20%) of DMSO or acetic acid first
• Consult the product specifications for solubility recommendations