Question

DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as

• A. Yellow bands
• B. Dark red bands
• C. Bright blue bands
• D. Orange bands

Answer 1

The correct option is D

Orange bands

The correct option is option D.

Explanation for correct option:

1. DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear bright orange.
2. They appear orange because ethidium bromide releases an orange fluorescence at $605\mathrm{nm}$ when exposed to UV light.
3. Ethidium bromide is the intercalating agent that stacks in between the nitrogenous bases.

Final answer: DNA strands on a gel stained with ethidium bromide appear bright orange when viewed under UV radiation.