Nucleic Acid Concentration Calculator

Calculate DNA and RNA concentrations from OD₂₆₀ spectrophotometer readings

Measurement Input

Batch Sample Entry

Sample IDOD₂₆₀OD₂₈₀OD₃₂₀DilutionConc (µg/ml)A₂₆₀/A₂₈₀Action
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What is Nucleic Acid Concentration?

This calculator determines DNA and RNA concentrations from UV spectrophotometry readings at 260nm. Different nucleic acid types have specific extinction coefficients for accurate concentration calculation.

How to Use This Calculator

  1. Select nucleic acid type (dsDNA, ssDNA, RNA, or Oligo)
  2. Enter OD₂₆₀ reading from spectrophotometer
  3. Add OD₂₈₀ for purity assessment (optional)
  4. Include dilution factor if sample was diluted
  5. View concentration in multiple units

Conversion Factors

dsDNA: 1 OD₂₆₀ = 50 µg/ml
ssDNA: 1 OD₂₆₀ = 33 µg/ml
RNA: 1 OD₂₆₀ = 40 µg/ml
Oligo: 1 OD₂₆₀ = 20-33 µg/ml

Purity Ratios

A₂₆₀/A₂₈₀ Ratio:

  • Pure DNA: 1.8-1.9
  • Pure RNA: 2.0-2.1
  • <1.8: Protein contamination
  • >2.1: RNA contamination or measurement error

Background Correction

OD₃₂₀ measures light scattering from particles. Subtract this value from OD₂₆₀ and OD₂₈₀ for more accurate measurements: Corrected OD₂₆₀ = OD₂₆₀ - OD₃₂₀

Tips for Accurate Measurement

  • Blank with the same buffer used for dilution
  • Use quartz cuvettes for UV measurements
  • Ensure readings are between 0.1-1.0 OD
  • Mix samples thoroughly before reading
  • Clean cuvettes between samples