Question

Upon exposure to UV radiation, DNA stained with ethidium bromide will show ______.

Options

• Bright blue colour

• Bright yellow colour

• Bright orange colour

• Bright red colour

Answer 1

Upon exposure to UV radiation, DNA stained with ethidium bromide will show bright red colour.

Explanation:

To visualise DNA, researchers use ethidium bromide, a stain that wedges itself between the DNA base pairs. When the gel is placed under UV light, this substance fluoresces, causing the DNA bands to glow with a vivid orange colour. This high-affinity interaction creates a strong signal, making it easy to identify and track the genetic fragments.