Zoology - Biotechnology - Principles and Processes Question with Solution | TestHub
Given below are four statements pertaining to separation of DNA fragments using gel electrophoresis. Identify the incorrect statements. 1. DNA is negatively charged molecule and so it is loaded on gel towards the anode terminal. 2. DNA fragments travel along the surface of the gel whose concentration does not affect movement of DNA. 3. Smaller the size of DNA fragment larger is the distance it travels through it. 4. Pure DNA can be visualised directly by exposing UV-radiation. Select the correct option from the followingNEET 2019 (Odisha)
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Solution:
Statements (1), (2) and (4) are incorrect because DNA fragments are negatively charged molecules they can be separated by forcing them to move towards the anode under an electric field through a medium/matrix. The concentration of gel does affect the resolution of DNA separation. 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. Only statement 3 is correct. The DNA fragments spearate (resolve) according to their size through sieving effect provided by the agarose gel. Hence, the smaller the fragment size, the farther it moves.
