Step-by-step guide to peptide reconstitution for laboratory research. Learn proper technique, concentration calculations, storage protocols, and common mistakes to avoid.
Reconstitution is the process of dissolving a lyophilized (freeze-dried) peptide powder into a liquid solution for laboratory use. Research-grade peptides are supplied as lyophilized powder because the dry form is significantly more stable than liquid solutions, allowing for long-term storage without degradation.
Before a lyophilized peptide can be accurately measured and dispensed for experiments, it must be dissolved in a suitable sterile solvent. This step is fundamental to nearly every peptide research protocol.
If you're new to peptide research, our guide on what peptides are provides helpful background.
Always verify your peptides come with a Certificate of Analysis (COA) confirming purity. Our guide on evaluating peptide vendors covers what to look for.
Work in a clean environment, ideally a laminar flow hood or designated clean bench. Wash hands thoroughly and wear nitrile gloves.
Remove the lyophilized peptide vial from cold storage (-20°C) and allow it to equilibrate to room temperature for 10–15 minutes. Do not remove the stopper until the vial has warmed.
Wipe the rubber stopper of both the peptide vial and the bacteriostatic water vial with an alcohol swab. Allow the alcohol to dry completely (~30 seconds).
Using an insulin syringe, draw your desired volume of bacteriostatic water. The volume determines the final concentration (see calculations below). Common starting volume: 1–2 mL.
Insert the needle through the stopper. Do not inject directly onto the powder. Aim toward the inside wall and let the water slide gently down the glass to prevent foaming and denaturation.
Let the vial sit undisturbed for 2–5 minutes. Do not shake or vortex. If needed, gently roll the vial between your palms or swirl slowly.
A properly reconstituted solution should be clear and free of visible particles. Persistent cloudiness may indicate a solubility issue requiring a different solvent or pH adjustment.
Concentration = Peptide Mass ÷ Solvent Volume
Adding 1 mL of BAC water to a 5 mg vial of Body Protection Compound 157: 5 mg ÷ 1 mL = 5 mg/mL. Each 0.1 mL (10 units) = 500 mcg.
Adding 1 mL of BAC water to a 10 mg vial of GLP-2: 10 mg ÷ 1 mL = 10 mg/mL. Each 0.1 mL (10 units) = 1 mg.
For more on stability, see what research shows about peptide safety.
Peptide reconstitution is dissolving a lyophilized peptide powder into a liquid solution using a sterile solvent such as bacteriostatic water before use in laboratory research.
Bacteriostatic water is the standard. It contains 0.9% benzyl alcohol as an antimicrobial preservative for multi-draw vials; the preservative does not slow chemical degradation of the peptide, and no fixed shelf life is claimed for reconstituted solutions.
Concentration = Peptide Mass ÷ Solvent Volume. Example: 10 mg ÷ 2 mL = 5 mg/mL.
No product-specific stability study has been performed, so no fixed shelf life is claimed. Keep reconstituted solutions refrigerated at 2–8°C, protected from light, and use them promptly; lyophilized powder at -20°C is far more stable than a solution.
Yes, but avoid repeated freeze-thaw cycles. Aliquot into single-use portions before freezing at -20°C.
Get everything you need for peptide reconstitution — research-grade peptides and bacteriostatic water with certificates of analysis.
Bacteriostatic Water Browse Research PeptidesAll compounds referenced in this guide are intended for laboratory research use only. Not approved for human or veterinary use.