Complete Guide to Peptide Reconstitution

Lyophilized (freeze-dried) peptides must be properly reconstituted before use in research applications. This comprehensive guide covers bacteriostatic water, step-by-step reconstitution, calculations, and best practices. --- Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol as a preservative. This solution is specifically formulated for laboratory settings and is the industry standard for reconstituting lyophilized peptides. | Property | Description | |----------|-------------| | Sterility | USP-grade sterile water meeting pharmaceutical standards | | Preservative | 0.9% benzyl alcohol prevents bacterial and fungal growth | | Multi-Use | Can be used multiple times while maintaining sterility | | pH Balance | Neutral pH suitable for peptide solutions | - Unopened: 24-36 months from manufacture date - After Opening: Use within 30-60 days - Storage: Room temperature (68-77°F), away from direct sunlight Plain sterile water should only be used for single-use applications. Without preservative, bacteria can grow after the first needle puncture, contaminating your peptide solution. --- Before beginning, gather these materials: - Lyophilized peptide vial - Bacteriostatic water (BAC water) with 0.9% benzyl alcohol - Sterile syringes (1mL insulin syringes work well) - Alcohol swabs for sanitization - Clean work surface --- - Clean your work surface with alcohol - Wash hands thoroughly or wear sterile gloves - Allow refrigerated BAC water to reach room temperature (10-15 minutes) - Wipe the rubber stopper of both the peptide vial and BAC water vial with alcohol swabs - Allow to air dry for 10-15 seconds - Using a sterile syringe, draw your desired volume of BAC water - Remove any air bubbles by tapping the syringe and pushing them out - Insert the needle through the rubber stopper at a slight angle - Critical: Aim the stream at the glass wall of the vial, NOT directly at the powder - Slowly release the water, letting it run gently down the side - This prevents damaging the peptide structure - Let the vial sit for 2-3 minutes - Do NOT shake the vial - this can denature the peptide - Gently roll the vial between your palms if needed - The solution should become clear with no visible particles --- Choose your volume based on desired concentration: | Amount of Peptide | BAC Water Added | Concentration | |-------------------|-----------------|---------------| | 5mg | 1mL | 5mg/mL (5000mcg/mL) | | 5mg | 2mL | 2.5mg/mL (2500mcg/mL) | | 10mg | 2mL | 5mg/mL (5000mcg/mL) | | 10mg | 5mL | 2mg/mL (2000mcg/mL) | Example calculation: If you have 5mg peptide and add 2mL BAC water: - Concentration = 5mg ÷ 2mL = 2.5mg per mL - Each 0.1mL (10 units on insulin syringe) = 250mcg --- Once reconstituted, peptides have a limited shelf life: | Storage Condition | Shelf Life | |-------------------|------------| | Refrigerated (2-8°C) | 2-4 weeks with BAC water | | Frozen (-20°C) | Not recommended | | Room tem