Final answer:
Ethidium Bromide (EtBr) is the most common dye used to visualize DNA. It has strong fluorescence and allows for the visualization of DNA bands on an agarose gel. However, it is a mutagen and potential carcinogen.
Step-by-step explanation:
The most common dye used to visualize DNA is Ethidium Bromide (EtBr) staining. EtBr is fluorescent and it interacts with the nucleobases in DNA, causing the DNA to "light up" when exposed to UV light.
Advantages of using EtBr staining include its strong fluorescence and the ability to visualize DNA bands on an agarose gel. However, EtBr is a mutagen and a potential carcinogen, so proper safety precautions must be taken while handling it.