A RAPID METHOD FOR PREPARATION OF ROUGH AND SMOOTH LIPOPOLYSACCHARIDEFROM BACTEROIDES, PORPHYROMONAS AND PREVOTELLA

We describe a new method for lipopolysaccharide (LPS) preparation by w ater extraction at 100-degrees-C and subsequent digestion with protein ase K. The crude LPS could be reliably used for immunoblotting since i t retained a high level of antigenicity, and was free of SDS and prote inase K, both of which can cause problems. Two monoclonal antibodies w hich failed to react with LPS prepared by two conventional methods rea cted well with our preparation. We used the new method to prepare LPS from 44 strains of bacteria formerly classified as Bacteroides, some o f which have been reclassified as Porphyromonas or Prevotella. In gene ral, yields were good, and electrophoretic profiles obtained with SDS- PAGE and silver staining enabled strains to be rated rough, semi-rough , or smooth.