W. Xu et al., STM IMAGING OF METAL-COATED CELL PLUGS OF THE ARCHAEOBACTERIUM METHANOSPIRILLUM-HUNGATEI GP1, Journal of Microscopy, 178, 1995, pp. 42-47
Scanning tunnelling microscopy (STM) images of Pt/Ir- and Pt/Ir/C-coat
ed cell plugs of Methanospirillum hungatei Showed paracrystalline stru
ctures with P6 symmetry and an 18-nm lattice constant, in agreement wi
th electron microscopy studies. The three-dimensional STM images unamb
iguously distinguished the two morphologically different proteinaceous
plug assemblies and led to an improved understanding of the natural i
nternal organization of whole plugs. Tip convolution effects and the g
rain size of the metal coating complicated interpretation of finer str
uctures, We discuss possible imaging mechanisms to explain observation
s in which part of the film was removed but the remaining part of the
structure was still imaged reproducibly.