Chitin is a polysaccharide found in the outer skeleton of crabs, insects, lobsters and shrimps and in the internal structures of other invertebrates. Chitin is composed of ß(1-4) linked units of the amino sugar N-acetyl-glucosamine, and is the main source of production of chitosan, which is used in applications such as a a wound healing agent, flocculating agent, a delivery vehicle for pharmaceuticals and genes, a sizing and strengthening agent for paper.