Lab Reference
Reconstitution Guide
Which solvent for which peptide? This guide covers recommended reconstitution solvents, storage conditions, and handling notes for every peptide in our catalogue.
Common Reconstitution Solvents
Bacteriostatic Water (BAC Water)
Sterile water containing 0.9% benzyl alcohol as a preservative. The gold standard for multi-dose peptide reconstitution — the benzyl alcohol inhibits microbial growth, allowing safe repeated needle entries over days to weeks.
Use when: Use for most peptides when the vial will be accessed multiple times.
Avoid: Not recommended for peptides highly sensitive to preservatives or for neonatal research models.
Sterile Saline (0.9% NaCl)
Isotonic sodium chloride solution without preservatives. Provides physiologically compatible osmolality but no antimicrobial protection.
Use when: Use for single-dose preparations or when the peptide will be administered immediately after reconstitution.
Avoid: Not suitable for multi-dose vials stored beyond 24 hours due to lack of preservative.
Phosphate-Buffered Saline (PBS)
Isotonic buffer solution maintaining pH 7.2-7.4. Provides both osmolality matching and pH stability, critical for pH-sensitive peptides and metallopeptides.
Use when: Use for sensitive peptides (LL-37, GHK-Cu, Semax) and when running pH-dependent assays.
Avoid: Avoid when phosphate interference could affect downstream assays (e.g., certain phosphate-sensitive binding experiments).
Peptide–Solvent Compatibility Table
Recommended solvents, storage conditions, and handling notes for each peptide. Click a row for details.
Storage times are conservative estimates for reconstituted peptides stored at the recommended temperature. Actual stability may vary by batch and handling conditions.
Best Practices
Add solvent slowly
Inject the solvent down the inside wall of the vial — never directly onto the lyophilized powder. This prevents foaming and denaturation.
Never shake or vortex
Agitation can break peptide bonds and cause aggregation. Gently swirl the vial or let it sit for 2-5 minutes to dissolve naturally.
Refrigerate immediately
Once reconstituted, peptides degrade much faster than in lyophilized form. Store at 2-8°C within minutes of preparation.
Aliquot for long-term storage
If you won't use the full vial within the recommended window, divide into single-use aliquots and freeze at -20°C. Avoid repeated freeze-thaw cycles.
Advanced: Adding Benzyl Alcohol to PBS
For multi-dose use of PBS-requiring peptides
Some researchers need the pH buffering of PBS but also require antimicrobial protection for multi-dose vials. Adding 0.9% benzyl alcohol (Ph. Eur. grade) to PBS is a valid approach used in research settings for peptides like GHK-Cu, Semax, and Selank.
- Concentration: Keep benzyl alcohol at exactly 0.9% (v/v). Higher concentrations risk peptide precipitation.
- Compatible peptides: GHK-Cu, Semax, Selank, and most other PBS-compatible peptides tolerate this combination well.
- Exception: LL-37 and other highly sensitive antimicrobial peptides — prepare fresh single-use aliquots in plain PBS instead.
- Storage: Refrigerate at 2-8°C and use within 30 days, the same as standard BAC water reconstitution.
Frequently Asked Questions
This guide is provided for research reference only. CertaPeptides products are sold strictly for laboratory research purposes and are not intended for human consumption. Always follow your institution's protocols and safety guidelines when handling research materials.