Research tools

Peptide Reconstitution Calculator

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

Peptide amount (mg)

Desired concentration (mg/mL)

Aliquot mass (mg)

Results

BAC water needed: 20.00 mL
Total aliquots: 20
Volume per aliquot: 1.00 mL1,000 µL

For in-vitro research, assay preparation and laboratory aliquoting only. Not human-use dosing guidance.

How to Reconstitute Lyophilized Peptides

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.

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

Wipe the vial stopper and BAC water vial top with an alcohol swab.
Using a graduated syringe, draw the calculated volume of BAC water.
Transfer the water slowly into the peptide vial, directing the stream against the glass wall — never directly onto the powder.
Gently swirl the vial until the powder is fully dissolved. Do not shake vigorously.
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-use reconstitution.
Do not freeze reconstituted peptides or expose them to direct light.
Higher concentrations mean smaller volumes per aliquot.

The math

BAC water (mL) = peptide amount (mg) ÷ desired concentration (mg/mL). Each aliquot's volume is the aliquot mass divided by the same concentration, and the number of aliquots is the peptide amount divided by the aliquot mass. For example, 5 mg at 2.5 mg/mL needs 2 mL of BAC water.