Agar-agar is a jelly-like substance, obtained from algae. Agar has been used as an ingredient in desserts throughout Asia. Agar is also used as a laxative, an appetite suppressant, a vegetarian substitute for gelatin, a thickener for soups, in fruit preserves, ice cream, and other desserts. In Labortories is is used as a solid substrate to contain culture media. Other uses are as a clarifying agent in brewing, and for sizing paper and fabrics. The gelling agent in agar is an unbranched polysaccharide obtained from the cell walls of some species of red algae, primarily from the genera Gelidium and Gracilaria. For commercial purposes, it is derived primarily from Gelidium amansii.