At Which Wavelength Do the Bases of DNA and RNA

Question

At which wavelength do the bases of DNA and RNA nucleotides absorb the most light?
A)200 nm
B)260 nm
C)280 nm
D)300 nm

Accepted Answer

The nitrogen-containing bases of DNA and RNA (adenine, guanine, cytosine, and thymine/uracil) have a characteristic absorption peak at 260 nm due to the presence of double bonds in their ring structures. This is known as the nucleic acid absorption peak and is commonly used to quantify nucleic acid concentration in biochemical assays. Therefore, wavelength 260 nm is the best choice where the bases of DNA and RNA nucleotides absorb the most light.