For research use only. This protocol is intended for qualified research professionals in controlled laboratory settings.
Understanding Lyophilisation
Research peptides are supplied in lyophilised (freeze-dried) form to maximise stability and shelf life. Lyophilisation removes water from the peptide solution through a process of freezing followed by sublimation under vacuum. The resulting dry powder is highly stable when stored correctly at -20°C and can maintain integrity for 24 months or longer in unopened vials.
Before using a peptide in research, it must be reconstituted by dissolving the lyophilised powder in an appropriate diluent. This process requires careful technique to avoid degradation, contamination, or foaming that can reduce the usable quantity of compound.
Equipment Required
- Lyophilised peptide vial (from -20°C storage)
- Bacteriostatic water for injection (0.9% benzyl alcohol) — for multi-use solutions
- Sterile water for injection — if using immediately or for single use
- Sterile insulin syringe (1mL, 28–31 gauge) for adding diluent
- 70% isopropyl alcohol wipes for sterilising vial tops
- Laminar flow hood or clean working environment
- Vortex mixer (optional — use with caution)
- Calculator for concentration calculations
- Labelling tape and permanent marker
Choosing Your Diluent
The choice of diluent depends on your research application and how quickly you will use the reconstituted solution:
- Bacteriostatic Water (0.9% Benzyl Alcohol) — Recommended for most research applications. The benzyl alcohol prevents microbial growth, extending the usable life of the reconstituted solution to approximately 28 days when refrigerated at 2–8°C. AE Peptides supplies pharmaceutical-grade bacteriostatic water.
- Sterile Water for Injection — Use when benzyl alcohol may interfere with your assay system, or when the solution will be used within 24 hours. Has no preservative — single-use only.
- Acetic Acid (0.1–1%) — Some hydrophobic peptides are poorly water-soluble and require dilute acetic acid for initial dissolution before further dilution in buffer. Check your specific peptide’s solubility profile.
- Phosphate-Buffered Saline (PBS) — Can be used for certain assay systems, though pH and ionic strength may affect peptide stability. Verify compatibility for your specific compound.
Calculating Your Reconstitution Volume
Before reconstituting, calculate the volume of diluent required to achieve your desired working concentration. Example calculation for a 10mg BPC-157 vial:
If you want a concentration of 1mg/mL:
Required volume = 10mg ÷ 1mg/mL = 10mL diluent
If you want a concentration of 2mg/mL:
Required volume = 10mg ÷ 2mg/mL = 5mL diluent
Consider how much solution you will realistically use within 28 days — unused reconstituted peptide should be discarded after this period. It is often better to reconstitute a portion of the lyophilised powder and store the remainder at -20°C.
Step-by-Step Reconstitution Protocol
- Allow the vial to reach room temperature — Remove the peptide vial from -20°C storage and allow it to equilibrate to room temperature for 15–30 minutes before opening. Opening a cold vial can cause moisture condensation that may affect the powder.
- Prepare your workspace — Clean the work surface with 70% isopropyl alcohol. Work in a laminar flow hood if available. Allow the alcohol to evaporate fully before proceeding.
- Sterilise the vial tops — Wipe the rubber stopper of both the peptide vial and the bacteriostatic water vial with a fresh alcohol wipe. Allow to air-dry for 30 seconds.
- Draw up the diluent — Using a sterile syringe, draw up the calculated volume of bacteriostatic water.
- Inject diluent slowly — Insert the needle into the peptide vial at an angle and direct the stream of liquid down the inner glass wall of the vial — not directly onto the powder. This prevents foaming and reduces mechanical stress on the peptide structure.
- Gently swirl to dissolve — Gently swirl the vial in a circular motion. Do not shake aggressively. Most peptides dissolve within 30–60 seconds. If the powder is not fully dissolving, continue gentle swirling or leave at room temperature for 5 minutes.
- Inspect the solution — The reconstituted solution should be clear and colourless (or characteristically coloured for specific peptides such as GHK-Cu). Any cloudiness, particulate matter, or unusual colour may indicate contamination or degradation.
- Label the vial immediately — Write the compound name, concentration, reconstitution date, and expiry date (28 days from reconstitution) on the vial.
- Store correctly — Refrigerate at 2–8°C, protected from light. Do not freeze the reconstituted solution if it contains bacteriostatic water — freezing can cause benzyl alcohol precipitation.
Common Mistakes to Avoid
- Injecting directly onto the powder — This causes turbulence and foaming, potentially denaturing surface-exposed peptide molecules.
- Vortexing aggressively — High-speed vortexing introduces air bubbles and mechanical shear stress. Gentle swirling is sufficient for most peptides.
- Not allowing the vial to warm to room temperature — Cold peptide powder can be slower to dissolve and condensation can introduce unwanted moisture.
- Using tap water or non-sterile diluents — Even trace contamination can degrade the peptide solution and introduce endotoxins that confound research results.
- Exceeding the 28-day shelf life — Reconstituted peptide solutions degrade over time even with preservatives. Always check the reconstitution date before use.
- Storing in a frost-free freezer — Frost-free freezers cycle through freeze-thaw repeatedly, which degrades peptide integrity.
Storage of Unreconstituted Peptides
Lyophilised peptide vials should be stored at -20°C in a desiccated environment away from light. They remain stable at 4°C (refrigerator) for several weeks, making short-term ambient storage practical. Upon receipt from AE Peptides, we recommend immediate transfer to -20°C storage unless the compound will be reconstituted within 1–2 weeks.
Each AE Peptides order includes a Certificate of Analysis specifying the compound-specific storage and handling recommendations. Always refer to the CoA for your specific batch.
This protocol is for educational and research purposes only. All compounds supplied by AE Peptides are for in-vitro laboratory research use only. Not for human or animal administration.