Question

$DNA$ staining by ethidium bromide is followed by the exposure to $UV$ rays. Now $DNA$ is seen as bands of

• A. Blue colour
• B. Orange colour
• C. Red colour
• D. Both B and C

Answer 1

Answer: (B)

• The separated DNA fragments can be visualised only after staining the DNA with a compound known as ethidium bromide followed by exposure to ultraviolet radiation (we cannot see pure DNA fragments in the visible light and without staining).
• Bright orange coloured bands of DNA in a ethidium bromide stained gel exposed to UV light is observed.