Identify the incorrect statement related to gel electrophoresis.
- Separated DNA fragments can be directly seen under UV radiation
- Separated DNA can be extracted from gel piece
- Fragment of DNA moves toward anode
- Sieving effect of agarose gel helps in separation of DNA fragments
Answer
(1) Separated DNA fragments can be directly seen under UV radiation
Solution
DNA fragments cannot be seen directly; they are visualised only after staining with ethidium bromide followed by exposure to UV radiation (bright orange bands).
The other statements are correct: bands are cut out and DNA is eluted from the gel piece; negatively charged DNA moves towards the anode; fragments separate by size due to the sieving effect of agarose gel.
Answer: (1)