Agarose extracted from sea weeds finds use in

Gel electrophoresis is a technique to separate fragments of DNA. Since 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. Now-a-days the most commonly used matrix is agarose which is a natural polymer extracted from seaweeds ( $e g$, Gelidium, Gracilaria, Gigartina, etc.).