[Electron microscopic investigations on encapsulated Staphylococci (author's transl)].

Attempts were made to study the surface of encapsulated staphylococci by electron microscopy. After fixation with osmium tetroxide the encapsulated staphylococci showed a "hazy" cell-surface, possibly because of capsular components (Fig. 1). On the other hand, the nonencapsulated staphylococci exposed a "smooth" surface of the cell wall (Fig 1). Similar findings were obtained after the immuneferritintechnique (Fig 2). The staphylococcal capsules could be clearly demonstrated by the "negative contrasting" method with ferritin (Fig 3). The capsules did not significantly enlarge after reaction of the encapsulated staphylococci with their homologous antiserum.