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Nucleic acids Practical

A260 concentration & purity calculator (A260/280, A260/230)

Calculate DNA/RNA concentration (ng/µL, µg/mL) and purity ratios (A260/280, A260/230) from A260/A280/A230 and dilution. Enter volume to see total amount.

All calculations run in your browser; data is not sent.

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How to use (3 steps)

  1. Select nucleic acid type (dsDNA/RNA, etc.) and enter A260/A280/A230.
  2. If measured with dilution, enter the dilution factor (no dilution = 1).
  3. Concentration and ratios appear automatically. Add volume to see total amount.

A260 factors and ratio guides vary by sample and conditions. They are shown as references; confirm with your assay.

Input (type, A260/A280/A230, dilution)

dsDNA=50 and RNA=40 are common guides. Use a custom factor if needed.

Blank correction (optional)

Many instruments already apply blank correction. Enable only if needed.

Results (concentration & ratios)

Results will appear here once you enter values.

Concentration (ng/µL)
Concentration (µg/mL)
A260/280
A260/230
Dilution factor
A260/280 guide: A260/230 guide:
About ratio guides (reference)

1 µg/mL = 1 ng/µL (same numeric value).

Ratio interpretation depends on the assay; this page does not make definitive judgments.

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How it’s calculated

FAQ

Is the dsDNA factor of 50 fixed?

It is a commonly used guide, but it can vary by sample and conditions. Use a custom factor if needed.

What do A260/280 and A260/230 indicate?

They are often cited as guides for protein or salt/solvent contamination, but they are not definitive.

What does entering volume show?

It calculates the total amount (ng/µg) in the tube from the concentration.

Do I need blank correction?

Many instruments correct internally. Enable it only if needed.

Is the data sent anywhere?

All calculations run in your browser; data is not sent.

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