Storage & Reconstitution Guide

Storing Lyophilized Peptides

Lyophilized (freeze-dried) peptides are remarkably stable when stored correctly. Most peptides remain viable for 12–24 months from the manufacture date when stored as follows:

• Temperature: Store at -20°C (a standard laboratory freezer) for long-term storage. Refrigeration at 2–8°C is acceptable for short-term storage of unopened vials.
• Light: Keep vials in their original packaging or stored in a dark, opaque container. UV exposure can degrade certain peptides.
• Moisture: Keep vials sealed and dry. Lyophilized peptides are hygroscopic — they absorb moisture from the air, which accelerates degradation.
• Stability: Do not subject lyophilized vials to repeated freeze-thaw cycles. Allow vials to reach room temperature before opening to prevent condensation inside the vial.

Before Reconstitution

Allow lyophilized vials to reach room temperature before reconstitution. This prevents condensation from forming inside the vial when the seal is broken, which can introduce moisture that affects subsequent storage stability.

Once at room temperature, briefly tap or flick the vial to dislodge any peptide powder from the rubber stopper or vial walls — this ensures all the lyophilized material is at the bottom of the vial before solvent is introduced.

Reconstitution Solvent

The standard solvent for research peptide reconstitution is bacteriostatic water (sterile water containing 0.9% benzyl alcohol as a preservative). Bacteriostatic water:

• Inhibits microbial growth, extending the usable life of reconstituted peptides
• Is compatible with the majority of research peptides at standard concentrations
• Provides a stable, well-characterized solvent matrix for laboratory work

For peptides that are insoluble in bacteriostatic water, alternative solvents such as sterile water for injection (SWFI), normal saline, or specific buffer solutions may be required. Always consult the peptide's specific solubility profile before selecting a solvent.

Reconstitution Protocol

Follow these steps for clean, reliable reconstitution:

1. Sanitize the work surface with 70% isopropyl alcohol. Sanitize the rubber stoppers of both the peptide vial and the bacteriostatic water vial.
2. Calculate your target concentration using our free reconstitution calculator. Most researchers target a working concentration that allows their standard dose to be drawn in a convenient syringe volume.
3. Draw the calculated volume of bacteriostatic water into a sterile syringe.
4. Inject the solvent into the peptide vial slowly, aiming the stream against the side of the vial rather than directly onto the lyophilized powder. This prevents foaming and protects fragile peptide structures.
5. Allow the vial to sit undisturbed for 30–60 seconds so the solvent can begin dissolving the peptide.
6. Swirl the vial gently in a circular motion to encourage complete dissolution. Do not shake vigorously — shaking can denature peptides and introduce air bubbles.
7. Visually inspect. A properly reconstituted peptide solution should be clear and free of particulates. If you see persistent cloudiness, undissolved material, or unusual coloration, contact us within 12 hours per our returns policy.

Storing Reconstituted Peptides

Once reconstituted, peptide solutions require careful storage to maintain stability:

• Refrigerate immediately at 2–8°C. Do not store reconstituted peptides at room temperature.
• Most reconstituted peptides remain stable for 2–4 weeks refrigerated. Specific stability varies by peptide and concentration — refer to individual peptide entries.
• For longer storage, reconstituted peptides can be aliquoted into smaller vials and frozen at -20°C or -80°C. Frozen reconstituted peptides typically remain stable for 3–6 months.
• Avoid repeated freeze-thaw cycles. Each freeze-thaw degrades a small fraction of the active peptide. If frozen storage is required, aliquot into single-use volumes before freezing.
• Protect from light by storing in opaque containers or wrapping vials in foil.

Signs of Degradation

Even properly stored peptides can degrade over time. Watch for these warning signs that a reconstituted peptide may no longer be reliable:

• Cloudiness or precipitation appearing in a previously clear solution
• Color change — yellowing, darkening, or any visible tint shift
• Visible particulates floating in the solution
• Odd smell when the vial is opened (most peptide solutions should be odorless)
• Reduced experimental potency compared to fresh reconstitutions

If you observe any of these signs, discard the vial and do not use it in research.

Common Mistakes To Avoid

• Shaking the vial vigorously after adding solvent — this denatures fragile peptide structures
• Reconstituting with tap water, distilled water, or unsterile water — introduces contamination and degrades stability
• Storing reconstituted peptides at room temperature for extended periods
• Repeated freeze-thaw cycles of reconstituted product
• Using expired bacteriostatic water — check the expiration date on the BAC water vial
• Mixing peptides in the same vial unless specifically validated — different peptides may have incompatible solubility profiles

Disposal of Used Vials

Used vials, syringes, and any reconstituted peptide that has expired or shown signs of degradation should be disposed of according to your local biohazard waste regulations. Sharps (needles, broken glass) require puncture-resistant containers. Liquid waste may require neutralization before disposal in many jurisdictions.

Quick Reference

• Lyophilized storage: -20°C, dark, dry, 12–24 months
• Reconstitution solvent: Bacteriostatic water (0.9% benzyl alcohol)
• Reconstituted storage: 2–8°C refrigerated, 2–4 weeks
• Frozen reconstituted storage: -20°C, 3–6 months, single-use aliquots
• Inspection window: Visually inspect within 12 hours of reconstitution
• Avoid: Vigorous shaking, repeated freeze-thaw, light exposure, room temperature storage

This guide is provided as a general reference for laboratory research practices. Individual peptides may have specific handling requirements that supersede these general recommendations. Always consult the specific peptide entry in our peptide glossary for product-specific guidance.