Question

Which one of the following statements is correct in the context of observing DNA separation by agarose gel electrophoresis?

Options

• DNA can be seen in visible light.

• DNA can be seen without staining in visible light.

• Ethidium bromide stained DNA can be seen in visible light

• Ethidium bromide stained DNA can be seen under UV light.

Answer 1

Ethidium bromide stained DNA can be seen under UV light.

Explanation:

When exposed to UV light, ethidium bromide fluoresces and emits visible light by intercalating between DNA base pairs. Fluorescence can be used to see DNA bands in gels, which appear orange.