Protein Dilution Calculator

How to Use the Protein Dilution Calculator

1. Select what you want to solve for using the mode buttons: Stock Volume (V1), Final Volume (V2), Stock Concentration (C1), or Final Concentration (C2).
2. Enter the three known values with their units — the selected solve target will be calculated.
3. Click Calculate Dilution to get the answer, volume ratio bar, and a step-by-step pipetting protocol.

About the C1V1 = C2V2 Formula

The dilution equation C1 × V1 = C2 × V2 expresses conservation of solute during dilution. The number of moles (or mass) of protein does not change — only the volume changes.

C1 = initial (stock) concentration, V1 = volume of stock taken, C2 = final (working) concentration, V2 = final total volume.

The diluent volume to add is always V2 − V1. If C1 and C2 are in the same units, V1 and V2 must also be in the same units for the equation to work correctly — this calculator handles all unit conversions automatically.

Note: C1 must always be greater than C2. You cannot dilute a protein to a concentration higher than the stock.

Common Protein Dilution Scenarios

• Western blot loading: Dilute protein samples to equal concentrations (e.g. 1 mg/mL) before loading onto SDS-PAGE.
• ELISA standard preparation: Serial dilution of stock protein antigen to prepare the standard curve.
• Enzyme assay setup: Dilute enzyme stock to a specific activity unit or concentration.
• Antibody dilution: Dilute primary or secondary antibodies from stock (e.g. 1 mg/mL) to working concentration (e.g. 1 µg/mL).
• Cell transfection: Dilute plasmid or protein into transfection reagent at a specific µg/mL concentration.