Extraction of Nucleic Acid-free Lipopolysaccharides from Gram-negative Bacteria

Abstract

THE extraction of Gram-negative bacteria by the hot phenol method of Westphal¹ yields a lipopolysaccharide along with considerable amounts of nucleic acid. The nucleic acid can be separated from the high molecular weight lipopolysaccharide by high-speed centrifugation, but to reduce the nucleic acid to a level of less than 2 per cent may require four or five sedimentations.