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FREE RESEARCH CALCULATOR

A260 DNA/RNA Concentration Calculator

Estimate dsDNA, ssDNA, or RNA concentration from A260 absorbance and sample dilution factor.

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CORE EQUATIONconcentration = A260 × factor × dilution
WHAT IT DOES

From formula to a bench-ready decision.

Convert an absorbance-at-260-nm reading into an approximate nucleic-acid mass concentration using conventional conversion factors.

Tossora Lab keeps units, intermediate values, and practical preparation checks visible so a mathematically correct answer is easier to translate into an experimental workflow.

BUILT-IN CHECKS

What Tossora Lab checks.

  • Uses separate conventional factors for dsDNA, RNA, and ssDNA.
  • Applies the user-entered dilution factor.
  • Keeps the conversion factor visible with the result.
BENCH NOTES

Before you use the result.

  • Follow the spectrophotometer method for path length, blanking, and valid absorbance range.
  • Treat the result as an absorbance-based estimate when contaminants or low signal may affect accuracy.

Research use only. Verify critical calculations, reagent specifications, route or instrument limits, and procedures against your approved protocol and institutional requirements.

COMMON USES

When this calculator is useful.

  • Estimating dsDNA concentration from an A260 measurement.
  • Applying a sample dilution factor to RNA or ssDNA absorbance.
  • Converting the absorbance estimate into the equivalent ng/µL value used at the bench.
WORKED CONTEXT

Example: dsDNA at A260 0.2 with a 10× dilution

Using the conventional dsDNA factor of 50 µg/mL per A260 unit, 0.2 × 50 × 10 gives 100 µg/mL. Numerically, 100 µg/mL equals 100 ng/µL.

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FAQ

Questions researchers often ask.

Which A260 conversion factors are used?

The calculator uses conventional approximate factors of 50 µg/mL per A260 for dsDNA, 40 for RNA, and 33 for ssDNA, before applying the entered dilution factor.

Does A260 alone prove the sample is pure?

No. Absorbance-based concentration can be affected by contaminants and measurement conditions. Purity assessment and instrument-specific quality checks are separate from this concentration conversion.

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