Which matrix is commonly used in gel electrophoresis?

Agarose

The correct answer is: (a) Agarose

Explanation:

Agarose is the commonly used matrix in gel electrophoresis. It is a natural polymer extracted from sea weeds and forms a gel-like matrix that allows DNA fragments to separate based on size through a sieving effect.

When an electric field is applied, the negatively charged DNA fragments move through the agarose gel towards the anode, and their migration is impeded by the gel's porous structure.

This separation of DNA fragments based on size is a fundamental technique in molecular biology and is widely used for various applications, including DNA analysis, DNA sequencing, and DNA fragment purification.