Proper reconstitution of lyophilized peptides is essential for maintaining bioactivity and preventing aggregation. This guide covers diluent selection, calculation methods, and best practices.

Equipment Needed

• Lyophilized peptide vial
• Bacteriostatic water (0.9% benzyl alcohol)
• Sterile syringe (1-3 mL)
• Alcohol swabs
• Clean work surface

Step-by-Step Protocol

1. Calculate volume: Volume (mL) = Mass (mg) / Desired concentration (mg/mL)
2. Clean vial top with alcohol swab
3. Draw BAC water into syringe
4. Inject slowly down the inside wall of the vial (NOT directly onto powder)
5. Gentle swirling (NEVER shake)
6. Wait for complete dissolution (5-15 minutes)
7. Inspect for clarity (no particles, no cloudiness)
8. Store at 2-8°C

Diluent Selection Guide

Diluent	Best For	Avoid With	Notes
BAC water	Most peptides	—	Standard choice
Sterile saline	Injection only	SPPS intermediates	No preservative
PBS buffer	Assays	Calcium-containing	Physiological pH
Acetic acid (0.1%)	Peptides with basic residues	—	May improve solubility
DMSO	Hydrophobic peptides	Injection	Research only

Common Mistakes

Mistake	Consequence	Fix
Shaking vial	Protein aggregation	Gentle swirl only
Direct injection onto powder	Mechanical shear damage	Inject down wall
Using sterile water	No preservation	Use BAC water
Wrong concentration	Dosing error	Use calculator
Re-freezing reconstituted	Ice crystal damage	Single-use aliquots

Quick Reference

Use the Reconstitution Calculator for exact volumes.

Reconstitution supplies available from Kingston Peptides