Electron Microscopy of Bacterial Endotoxin-Antibody Complexes by the Use of Ferritin-Conjugated Antibody

Abstract

The molecular shape of bacterial endotoxin extracted from the cell walls with phenol-water or trichloroacetic acid (TCA) method has been observed in the electron microscope. Electron micrographs of negatively stained macromolecules of highly toxic endotoxin extracted from the cell walls of Escherichia coli strain 0113 with phenol-water revealed filamentous structures with a diameter of 100 Å in width. On the other hand, the micrographs of endotoxin extracted from the whole cells with cold TCA revealed a mixture of filaments and discs. In a precipitate formed by a reaction mixture of filamentous lipo-polysaccharides and ferritin-conjugated antibodies, a specific combination of lipopolysaccharides and antibody molecules has been observed.