Reconstitution Calculator

Calculate how much bacteriostatic water to add to your lyophilized peptide for your desired concentration.

Free Peptide Reconstitution Calculator

This free online calculator computes the exact volume of bacteriostatic water (BAC water) needed to reconstitute a lyophilized research peptide to a desired concentration. Enter the peptide amount in milligrams, your target concentration in mg/mL, and your desired aliquot mass — the calculator returns the BAC water volume, total number of aliquots, and volume per aliquot. Results can be copied to clipboard or printed as a protocol card for bench reference.

Laboratory research use only. This calculator is provided for in-vitro research, assay preparation, and laboratory aliquoting. It is not intended to provide medical or human-use dosing guidance.

How to Reconstitute Lyophilized Peptides

Reconstitution is the process of adding a solvent — typically bacteriostatic water (BAC water) — to a lyophilized (freeze-dried) peptide powder to produce a solution at a known concentration suitable for laboratory aliquoting and assay preparation.

Step-by-Step Guide

  1. Wipe the vial stopper and BAC water vial top with an alcohol swab.
  2. Using a graduated syringe, draw the calculated volume of BAC water.
  3. Transfer the water slowly into the peptide vial, directing the stream against the glass wall — never directly onto the powder.
  4. Gently swirl the vial until the powder is fully dissolved. Do not shake vigorously.
  5. Store the reconstituted solution at 2–8°C, protected from light, and use within 30 days for stability-sensitive compounds.

Key Tips

  • Always use bacteriostatic water (0.9% benzyl alcohol) — not sterile water — for multi-dose reconstitution.
  • Do not freeze reconstituted peptides or expose them to direct light.
  • Higher concentrations mean smaller injection volumes per dose.