Reconstitution Calculator

How to reconstitute a lyophilized protein or peptide

1. Choose whether to find the volume to add for a concentration, or the concentration from a volume.
2. Enter the amount in the vial from its label or data sheet, and the target concentration or the volume you will add.
3. Add the molecular weight to see the molar concentration, and an aliquot volume to see how many aliquots you get.

Frequently asked questions

What is the formula?

Volume = amount ÷ concentration. 1 mg dissolved to 1 mg/mL needs 1 mL; 100 µg to 0.5 mg/mL needs 200 µL.

Which solvent should I use?

The one on the data sheet: often sterile water or a buffer such as PBS, and sometimes a little acetic acid, DMSO or another solvent for peptides that do not dissolve in water.

Should I vortex it?

Spin the vial down first so the powder is at the bottom, add the solvent down the side, and mix gently by swirling or slow pipetting. Vigorous vortexing can denature proteins.

Why aliquot?

Freezing and thawing a stock again and again can damage a protein. Split it into single-use aliquots and keep them frozen.