title: Adaptation of a high-voltage electron microscope for routine biological dark-field imaging.
abstract: Relative merits of different objective aperture geometries for generating dark-field images in a high-voltage electron microscope (an AEI EM7) are considered. Using metal-bar beam stops in the objective lens diffraction plane, with large (500 micron diameter) limiting apertures, effective resolution in the 2-4 nm range can be demonstrated for biological specimens.
mesh_terms: D000818:Animals; D001921:Brain / Q000648:ultrastructure*; D008854:Microscopy, Electron / Q000295:instrumentation* / Q000379:methods; D051381:Rats; D013194:Staining and Labeling; D013604:T-Phages / Q000648:ultrastructure*