Visualization of bacterial polysaccharides by scanning transmission electron microscopy.
Highly purified capsular polysaccharides of Neisseria meningitidis groups A, B, and C have been visualized by high resolution Scanning Transmission Electron Microscopy (STEM). Spheroidal macromolecules approximately 200 A in diameter are characteristic of the Meningococcus A and C polysaccharides whereas filaments that are 400-600 A in length are found in Meningococcus B polysaccharide preparations. Filaments are occasionally found associated with the spheroidal Meningococcus A and C polysaccharides and it is proposed that these structures are composed of a long (1-4 microns) filament or filaments that are arranged in spheroidal molecules or micelles of high molecular weight. The Meningococcus B polysaccharide, by contrast, is a short flexuous filament or strand of relatively low molecular weight. A relationship between morphology and antigenicity is proposed.
D005612:Freeze Drying; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D009345:Neisseria meningitidis / Q000032:analysis / Q000648:ultrastructure*; D011135:Polysaccharides, Bacterial / Q000032:analysis*; D013194:Staining and Labeling
D011135:Polysaccharides, Bacterial