Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Extracellular polysaccharide is a virulence factor of the most cariogenic bacteria, Streptococcus mutans. We describe a procedure for chemical analysis of this polysaccharide of S. mutans, using a well-known glucan synthesized by purified enzymes of cariogenic streptococci. Soluble and insoluble glucan from glucosyltransferase D and B respectively, were prepared and analyzed by nuclear magnetic resonance spectroscopy and methylation. Soluble alpha-glucan contained 60% of (1 -> 6)-linkages and 17% of branching while insoluble alpha-glucan was composed of 57% of (1 -> 3)- and 28% of (1 -> 6)-linkages with 8% branching. The described procedure could be important focusing future studies on in vivo biofilm. (C) 2010 Published by Elsevier B.V.465551554Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [152302/2007-7]