State the principle underlying 'gel electrophoresis' and mention the applica-tion of this technique in biotechnology .

Explanation

The principle underlying gel electrophoresis is that when a bio-molecule like DNA is placed in a gel matrix (agarose gel) under an electric field , the molecule separates according to their charge and size. It Is widely used in the separation of fragments produced as a result of restriction endonuclease digestion.