DNA/RNA Concentration Calculator
Calculate the concentration of double-stranded DNA, single-stranded DNA, or RNA in your samples based on A260 absorbance and dilution factor.
Measurement Parameters
Specify absorbance, dilution factor, and sample type.
Nucleic Acid Concentration
* Equal to 250.0 ng/μL.
Expert Tip
For accurate concentration measurements, ensure A260 readings are between 0.1 and 1.0. If readings exceed 1.0, dilute your sample further and recalculate.
Methodology & Beer-Lambert Equivalents
Concentration Calculation
Under standard 10 mm path length, the concentration of nucleic acids is computed by multiplying the absorbance (optical density) at 260 nm by the standard conversion factor:
Standard Conversion Factors
An absorbance of 1.0 (A260 = 1) in a 1 cm cuvette corresponds to:
- Double-stranded DNA (dsDNA): 50 μg/mL
- Single-stranded DNA (ssDNA): 33 μg/mL
- RNA: 40 μg/mL
How to Calculate DNA Concentration from Absorbance
Spectrophotometric absorbance at 260 nm (A260) is the standard method to quantify nucleic acids:
Measure Absorbance at 260 nm
Record the spectrophotometer output at 260 nm. Ensure background correction is performed.
Select Nucleic Acid Type Factor
Use the constant conversion factor: dsDNA = 50 µg/mL, ssDNA = 33 µg/mL, RNA = 40 µg/mL per A260 unit.
Apply the Dilution Factor
Multiply the absorbance by the factor and dilution factor: Concentration = A260 × Factor × Dilution Factor.
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