Fig. 6

Immunoelectron microscopy of tau-positive oligodendroglia-like cells. Oligodendroglia-like cells a labeled with AT8/diaminobenzidine (DAB, Scale bar, 1 μm). Nickel (Ni) ammonium sulfate was used to enhance the DAB signals. A higher magnification image of the white box in the upper left of a is shown in b and shows AT8 labelled 20–25 nm diameter straight filaments (scale bar:0.2 μm). The specificity of this labeling was confirmed by energy-dispersive X-ray (EDX) analysis. A nickel peak (Ni+) was detected in areas with DAB precipitates (area c) but not in background areas (Ni-, area d). EDX mapping of this Ni peak identified areas labeled specifically by DAB (e, Ni, purple). In contrast, EDX mapping for osmium (f, Os, cyan), lead (g, Pb, red) and uranium (h, U, green), identified background electron-dense areas. For a high resolution image of Fig. 6 please see Additional file 1