Question

Following are the four statements regarding separation of DNA fragments using Gel electrophoresis. Identify the INCORRECT statements.

i. DNA is negatively charged molecule and so it is loaded on gel towards the Anode terminal.

ii. DNA fragments travel along the surface of the gel whose concentration does not affect movement of DNA.

iii. Smaller the size of DNA fragment, larger is the distance it travels through it.

iv. Pure DNA can be visualized directly by exposing to UV radiation.

Options

• i, ii and iv

• i, ii and iii

• i, iii and iv

• ii, iii and iv

Answer 1

i, ii and iv

Explanation:

DNA is a negatively charged molecule that is put onto the gel towards the cathode terminal and then moves to the anode terminal during electrophoresis.

The migration speed of DNA through the gel slows as the concentration of the gel rises. Only after staining with the right stain can DNA fragments be seen under UV light (e.g. Ethidwn bromide).