What this calculator does
DNA/RNA concentration from A₂₆₀ works out nucleic acid concentration from a spectrophotometer absorbance reading. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaC = A₂₆₀ × CF × DF (CF: dsDNA 50, ssDNA 33, RNA 40 µg/mL per A₂₆₀ unit)
The inputs explained
| Field | What to enter |
|---|---|
| A₂₆₀ reading | A number. Starts at 0.85. |
| Dilution factor | A number. Starts at 1. |
| Sample type | Choose from dsDNA (CF 50), ssDNA (CF 33), RNA (CF 40). |
| Sample volume (µL) | A number, measured in µL. Starts at 50. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with a₂₆₀ reading
Every other input is held at the calculator’s starting values while a₂₆₀ reading varies. Select any row to load that scenario into the calculator.