Name and explain the technique used for separating DNA fragments and making them available for biotechnology experiments.
Solution
Gel electrophoresis is a technique which is used for separating DNA fragments in a gel on the basis of their electric charge and size.
The process of gel electrophoresis is as follows:
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The fragments obtained after cutting with restriction enzymes are separated by using gel electrophoresis.
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Electric field is applied to the agarose gel matrix and the negatively-charged DNA fragments move towards the anode.
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Fragments separate according to their size by the sieving properties of agarose gel. The smaller the fragment, the farther it moves.
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Staining dyes such as ethidium bromide, upon exposure to UV radiation, are used to visualise the DNA fragments.
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DNA fragments are visible as bright orange-coloured bands in the agarose matrix.
- These bands are cut from the agarose gel and extracted from the gel piece (elution).
- DNA fragments are purified and used in constructing recombinant DNAs.
