DNA / RNA Concentration Calculator
Calculate nucleic acid concentration from absorbance at 260 nm using standard conversion factors for dsDNA, ssDNA, and RNA.
How to Use the DNA Concentration Calculator
- Measure the absorbance of your sample at 260 nm.
- Enter the A260 value.
- Enter the dilution factor (1 if undiluted).
- Select the nucleic acid type.
- Click Calculate to get the concentration in ng/µL.
使用场景
- •Quantifying DNA after extraction or PCR purification.
- •Assessing RNA quality before RT-PCR or sequencing.
- •Determining nucleic acid yield for cloning and transfection experiments.
公式
Formula: concentration (ng/µL) = A260 × dilution factor × conversion factor. Factors: dsDNA = 50, ssDNA = 33, RNA = 40.
常见问题
Why is 260 nm used for nucleic acids?
Nucleobases absorb UV light maximally at ~260 nm. This absorbance is directly proportional to nucleic acid concentration per Beer-Lambert law.
What is a good A260/A280 ratio?
Pure DNA should have A260/A280 ≈ 1.8; pure RNA ≈ 2.0. Lower ratios indicate protein contamination. Use NanoDrop or similar for accurate purity assessment.
Disclaimer
For educational and laboratory purposes only. Concentration estimates assume pure nucleic acid solutions. Contaminants can significantly affect absorbance readings.