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प्रश्न
Name and describe the technique that helps in separating the DNA fragments formed by the use of restriction endonuclease
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उत्तर
Gel electrophoresis is a technique of separating DNA fragments formed by the action of restriction endonucleases.
The fragments of DNA are placed in a typical agarose gel under an electric field. The DNA fragments move towards the anode as these fragments are negatively charged molecules. The DNA fragments separate according to their size through the sieving effect provided by the agarose gel. The smaller the fragment size, the farther it moves. The separated DNA fragments are stained with ethidium bromide followed by exposure to ultraviolet radiation. The DNA fragments are seen as orangecoloured and are cut out from the agarose gel and extracted from the gel piece. This step is called elution.
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संबंधित प्रश्न
How are 'sticky ends' formed on a DNA strand? Why are they so called?
How does a restriction nuclease function? Explain
There is a restriction endonudease called as EcoRI. What does co part in it stands for?
Which of the following statements does not hold true for restriction enzyme?
What does H in’ ‘d’ and ‘III’ refer to in the enzyme Hind III?
Restriction enzymes should not have more than one site of action in the cloning site of a vector. Comment.
Carefully observe the given picture. A mixture of DNA with fragments ranging from 200 base pairs to 2500 base pairs was electrophoresed on agarose gel with the following arrangement.
(a) What result will be obtained on staining with ethidium bromide? Explain with reason.
(b) The above setup was modified and a band with 250 base pairs was obtained at X.
What change(s) were made to the previous design to obtain a band at X? Why did the band appear at position X?
Given below is the restriction site of a restriction endonuclease Pst-I and the cleavage sites on a DNA molecule.
\[\ce{5' C - T - G - C - A \overset{\downarrow}{-}{G 3'}}\]
\[\ce{3' G\underset{\uparrow}{-} A - C - G - T - C 5'}\]
Choose the option that gives the correct resultant fragments by the action of the enzyme Pst-I.
In the restriction endonuclease EcoRI, what do the letter 'R' and the Roman numeral 'I' represent?
Why is it mandatory to cut both the vector DNA and the foreign source DNA with the exact same restriction enzyme when constructing recombinant DNA?
