How It Works
This calculator works in 4 steps.
Enter the measured concentration
Type the ng/µL value from the spectrophotometer or fluorometer.
Enter the target
Type a target ng/µL, or a target mass such as 100 ng.
Enter the final volume
Type the total volume in µL.
Read the volumes
The calculator returns DNA and buffer volumes and flags DNA volumes under 1 µL.
The Formula
The formula applies C₁V₁ = C₂V₂ in ng/µL and converts A260 when needed.
V_DNA = C₂ × V₂ / C₁dsDNA (ng/µL) = A260 × 50 × DFV_DNA = m (ng) / C₁- C₁:
- Measured DNA concentration (ng/µL)
- C₂:
- Target concentration
- V₂:
- Final volume (µL)
- m:
- Target DNA mass (ng)
Diluting 250 ng/µL plasmid to 10 ng/µL in 50 µL needs 2 µL DNA and 48 µL TE buffer.
Conversion Table
The conversion table gives DNA and buffer volumes for 6 nucleic acid dilutions.
| Stock | Target | Final volume | DNA volume | Buffer |
|---|---|---|---|---|
| 250 ng/µL | 10 ng/µL | 50 µL | 2 µL | 48 µL |
| 1,200 ng/µL | 50 ng/µL | 20 µL | 0.8333 µL | 19.17 µL |
| 85 ng/µL | 5 ng/µL | 100 µL | 5.882 µL | 94.12 µL |
| 500 ng/µL | 1 ng/µL | 100 µL | 0.2 µL | 99.8 µL |
| 35 ng/µL | 2 ng/µL | 25 µL | 1.429 µL | 23.57 µL |
| 2,000 ng/µL | 100 ng/µL | 10 µL | 0.5 µL | 9.5 µL |
What Is the DNA Dilution Calculator?
The DNA Dilution Calculator is a tool that returns the DNA volume and buffer volume needed to reach a working nucleic acid concentration in ng/µL, or a set mass in a set volume. The calculator accepts concentrations from absorbance at 260 nm (A260) or from fluorometric assays.
An A260 of 1.0 equals about 50 ng/µL of double-stranded DNA (dsDNA) in a 1 cm path. Fluorometric dyes measure dsDNA alone and read lower than A260 when RNA or free nucleotides are present. The calculator works with either value and recommends Tris-EDTA (TE) or 10 mM Tris buffer as the diluent for storage.
Common Uses
There are 5 main uses of this calculator.
PCR templates
Users dilute genomic DNA to 1 to 10 ng/µL for PCR.
Library preparation
Sequencing labs bring DNA to the input mass of a kit.
Transformation
Users dilute plasmid to 1 ng/µL for competent cells.
Sanger sequencing
Labs dilute templates to the provider's ng/µL range.
Cloning reactions
Researchers set vector and insert at defined ng amounts.