Upon exposure to UV radation, DNA stained with ethidium bromide will show:

Gel electrophoresis is generally done to separate the DNA fragments on Agarose gel. The negatively charged DNA migrate to the positive side when an electric field is applied. The migration depends on the size of the DNA fragment. Smaller DNA move farther as compared to larger fragments. The DNA fragments are stained with EtBr (Ethidium bromide) and exposed to UV-light. This gives bright orange colour to the bands.