Read the following Assertion and Reason and choose the correct option. Assertion: The matrix used in gel electrophoresis should have controllable pore size. Reason: Agarose concentration can be changed to change pore sizes.

Step-by-step solution

Nowadays the most commonly used matrix is agarose which is a natural polymer extracted from sea weeds. The DNA fragments separate (resolve) according to their size through sieving effect provided by the agarose gel. Hence, the smaller the fragment size, the farther it moves.