DNA Concentration Calculator

Calculate DNA concentration from absorbance readings using Beer's Law and determine DNA purity ratios.

Spectrophotometer Readings

Enter 1 if no dilution, or the dilution factor used

Results

Enter absorbance readings to calculate concentration

DNA Concentration Calculations

Extinction Coefficients

  • • dsDNA: 50 μg/mL per A260 unit
  • • ssDNA: 33 μg/mL per A260 unit
  • • RNA: 40 μg/mL per A260 unit
  • • Formula: C = A260 × ε × DF

Purity Ratios

  • • A260/A280: 1.8-2.0 (pure DNA)
  • • A260/A230: >2.0 (clean DNA)
  • • Lower ratios indicate contamination
  • • Protein contamination lowers A260/A280