260/280 ratio is a potential measurement for the detection and quantify of DNA / RNA.
The ratio of absorbance at 260 nm and 280 nm is used to assess the purity of DNA and RNA extractions. That is because Nucleic acids shows the highest absorbance generation/highest UV radiation absorbance at 260 nm and maxima at 280 nm.
It can also be used to check whether its contaminated.
A 260/280 ratio between 1.8 – 2.0 is generally accepted as “pure” DNA/RNA.
If the ratio is below 1.8 then it can indicate the presentence of proteins or phenyl contamination.