Preparation of the Specific Polysaccharide of Type I Pneumococcus

Abstract

It was shown1 that preparation of the specific polysaccharides of Types II and III pneumococcus in the cold and without the use of strong acid or alkali gave products forming much more viscous solutions than did the polysaccharides isolated by the older methods,2 but apparently differing otherwise from the older preparations only in their ability to precipitate more antibody from homologous rabbit antisera. These differences were attributed to the greater chain length of the molecules of the new preparations.The acetyl polysaccharide from Type I pneumococcus has now been similarly prepared. This product had the chemical and physical properties of the acetyl polysaccharide reported by Avery and Goebel3 but gave solutions of much higher viscosity than did samples prepared according to Reference 3, and precipitated twice as much antibody nitrogen from a Type I antipneumococcus rabbit serum. Thus a solution of the new preparation, S 120, containing 1 mg. per ml. in 0.9% saline had a relative viscosity, ηr, of...