Agar is a natural polymer extracted from red alga Rhodophyceae, primarily, consisting of alternative D- and L-galactose units. This type of high gel strength agar is used when a firmer gel is required and mostly suitable for plant cell culture.
Agar is a polysaccharide complex obtained through bleaching and hot water extraction of agarocytes from the red alga Rhodophyceae, found in the Pacific and Indian Oceans and the sea of Japan. The genera Gelidium, Acanthopeltis, Ceramium, Pterocladia and Gracilaria predominate in agar production. Agar is composed of about 70% agarose and 30% agaropectin.