Carbohydrates are universally present on the surface of living cells. On eukaryotic cells, many different carbohydrates are attached as glycoproteins and glycolipids; the oligosaccharide moieties are known to act as receptors and it seems likely that they play an important role in cell-to-cell recognition processes. Polysaccharide capsules, in prokaryotes characteristically composed of repeating oligo saccharides, are found on the surface of many bacteria. These capsules are typically composed of only one polysaccharide and lie outside the outer membrane of gram-negative cells and the peptidoglycan layer of gram-positive cells. In general, individual bacteria do not exhibit variation of these antigens as has been described for the variant glycoproteins of trypanosomes (CROSS 1978). Comprising 99% water, these highly hydrated, polyanionic polysaccharide capsules serve many functions. These include determining access of molecules and ions to the bacterial cell envelope and the cytoplasmic membrane, the promotion of adherence to the surfaces of inanimate objects or living cells and the formation of biofilms and microcolonies (COSTERTON and IRWIN 1981). Among certain gram-positive and gram-ncgative bacteria, capsules have evolved distinctive structural and functional characteristics which are of cardinal importance in the pathogenesis of infections of animals, plants and insects (SUTHERLAND 1977).