Agar A: 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 in 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. Agarose: A neutral gelling fraction which consists of a linear polymer of alternating D-galactose and 3,6-anhydrogalactose units. Agaropectin: A non-gelling fraction which consists of 1,3-glycosidically linked D-galactose units, some of which are sulfated at position 6. Agar-A is bacteriology grade agar of highest quality