Free research tool
Reconstitution calculator
Vial strength, diluent volume and target amount in; the concentration, the volume in mL and the syringe graduation out, for your lab records.
Calculator
Your vial
Enter the figures printed on the label and the amount you are working with.
Bacteriostatic water
For your lab records
Syringe graduation
0on the U-100 scale
- Volume
- 0 mL
- Concentration
- 0 mg / mL
- Scale
- U-100 · 100 per mL
Marked on a U-100 scale
Research calculation only, not dosing guidance. Assumes a fully dissolved solution; U-100 = 100 graduations per mL, U-40 = 40 graduations per mL.
How to reconstitute a vial
Add the diluent
Using a sterile needle, slowly run the chosen volume of bacteriostatic water down the inside wall of the vial, never directly onto the lyophilised powder.
Swirl, do not shake
Gently swirl the vial until the powder completely dissolves. Shaking can degrade the peptide. Allow a few minutes if needed.
Work out the volume
Use the calculator above to find the volume in mL for your target amount, and the matching graduation on a U-100 or U-40 scale.
Record and label
Note the concentration and the date in your lab records and on the vial. Store the remaining solution at 2–8 °C, away from light.
Reconstitution questions
Diluents, graduation scales and storage.
Bacteriostatic water (BW) is sterile water preserved with 0.9% benzyl alcohol. The preservative inhibits bacterial growth, allowing multi-use vials to remain stable for up to 28 days after opening — unlike regular sterile water which should be used once.
They are two graduation scales. A U-100 syringe is marked with 100 graduations per mL; a U-40 syringe with 40 graduations per mL. The calculator converts the same volume in mL to the matching mark on whichever scale your lab uses.
Store reconstituted peptides in the refrigerator at 2–8 °C, away from light. Most peptides remain stable for 4–6 weeks when refrigerated. Never freeze a reconstituted peptide — freeze-thaw cycles degrade the compound.
Normal saline (0.9% NaCl) can be used, but because it contains no preservative the reconstituted solution should be used within 24 hours. Bacteriostatic water is preferred for multi-use vials.
