How It Works
This calculator works in 4 steps.
Enter the stock
Type the stock value and choose mg/mL, µg/mL, % w/v, or ×.
Enter the working concentration
Type the strength from the staining protocol.
Enter the volume
Type the volume of staining solution, gel, or buffer.
Read the stock volume
The calculator returns µL or mL of stock to add.
The Formula
The formula applies C₁V₁ = C₂V₂ with mass, percent, or × units.
V₁ = C₂ × V₂ / C₁V₁ = V₂ × X_work / X_stock1 mg/mL = 1,000 µg/mL- C₁ / C₂:
- Stock and working stain concentration
- X_stock / X_work:
- × strengths
- V₂:
- Working volume
1 µg/mL DAPI in 10 mL PBS from a 5 mg/mL (5,000 µg/mL) stock needs 1 × 10 / 5,000 = 0.002 mL (2 µL).
Conversion Table
The conversion table gives stock volumes for 6 common stain preparations.
| Stain | Stock | Working | Volume | Stock to add |
|---|---|---|---|---|
| DAPI | 5 mg/mL | 1 µg/mL | 10 mL | 2 µL |
| Hoechst 33342 | 10 mg/mL | 2 µg/mL | 5 mL | 1 µL |
| SYBR-type gel stain | 10,000× | 1× | 50 mL | 5 µL |
| Propidium iodide | 1 mg/mL | 5 µg/mL | 1 mL | 5 µL |
| Crystal violet | 1% w/v | 0.1% w/v | 100 mL | 10 mL |
| Ethidium bromide | 10 mg/mL | 0.5 µg/mL | 100 mL | 5 µL |
What Is the Stain Dilution Calculator?
The Stain Dilution Calculator is a tool that dilutes a stain or dye stock to a protocol-defined working concentration, expressed as µg/mL, % w/v, or × strength. The calculator applies C₁V₁ = C₂V₂ and handles × labels such as 10,000× gel stains.
Stain protocols specify working strength, such as 1 µg/mL DAPI for nuclear staining or 1× for a 10,000× nucleic acid gel stain. The calculator converts the label form and returns the stock volume. Many nucleic acid stains bind DNA, so the calculator prints the reminder to handle them under the supplier's safety data sheet (SDS).
Common Uses
There are 5 main uses of this calculator.
Nuclear staining
Cell biologists dilute DAPI and Hoechst for imaging.
Gel staining
Users add 10,000× stains to agarose gels.
Viability dyes
Flow labs dilute propidium iodide for dead cell exclusion.
Gram staining
Microbiologists prepare crystal violet and safranin working solutions.
Biofilm assays
Researchers stain biofilms with 0.1% crystal violet.