How to Use the DNA / RNA Concentration Calculator
Calculate nucleic acid concentration and evaluate purity ratios:
Enter Absorbance A₂₆₀
Input UV spectrophotometer optical density reading at 260 nm.
Enter Absorbance A₂₈₀
Input UV absorbance at 280 nm to calculate protein contamination ratio.
Select Nucleic Acid
Choose dsDNA (50 µg/mL), ssDNA (33 µg/mL), or RNA (40 µg/mL).
View Concentration
Get concentration in µg/mL (ng/µL) and purity rating.
Key Features & Spectrophotometry Math
Beer-Lambert Extinction Factors
Applies standard extinction coefficients (50 for dsDNA, 40 for RNA).
A260/A280 Purity Diagnosis
Diagnoses protein, phenol, or cellular RNA cross-contamination instantly.
100% Private Client Compute
Runs in browser memory with zero tracking or server logs.
Spectrophotometry Guide: Quantifying DNA & RNA Concentration
UV spectrophotometry relies on the principle that purine and pyrimidine bases in nucleic acids absorb UV light maximally at 260 nm. An $A_260$ reading of 1.0 corresponds to approximately 50 $\mu$g/mL of double-stranded DNA or 40 $\mu$g/mL of single-stranded RNA.
Frequently Asked Questions
?What does a low A260/A280 ratio indicate?
A ratio below 1.6 indicates protein, phenol, or reagent contamination in the nucleic acid sample.