Agarose is an unmodified polysaccharide of galactose with neutral charge, which is essential to prevent interactions with charged DNA and protein molecules. It forms large pores which is useful for separation of DNA and proteins by its molecular size. In aqueous solution, below 35°C these polymer strands are held together in a porous gel structure by non-covalent interactions like hydrogen bonds and electrostatic interactions. On heating the solution, these non-covalent interactions are broken down and the strands are separated. As the solution cools, these non-covalent interactions are re-established and the gel is formed. The density or pore size of which is determined by concentration of agarose.