In gel electrophoresis, the process of cutting out and extracting the separated bands of DNA from the gel piece is called:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Elution
In gel electrophoresis, DNA fragments separate in an agarose gel according to their size. They become visible after staining with ethidium bromide and exposure to UV light, as bright orange bands. The bands are then cut out of the gel and the DNA is extracted from the gel piece. This step is called elution. The purified fragments are joined with cloning vectors to make recombinant DNA.
NCERT Extract:
Restriction Enzymes – “… The separated DNA fragments can be visualised only after staining the DNA with a compound known as ethidium bromide followed by exposure to UV radiation (you cannot see pure DNA fragments in the visible light and without staining). You can see bright orange coloured bands of DNA in a ethidium bromide stained gel exposed to UV light (Figure 9.3). The separated bands of DNA are cut out from the agarose gel and extracted from the gel piece. This step is known as elution. The DNA fragments purified in this way are used in constructing recombinant DNA by joining them with cloning vectors.”