Electron phase and amplitude images of stained biological thin sections

Very-high-resolution electron microscopy demonstrates similar phase image 'particles' in uncontaminated, unsupported thin sections of epoxy-embedded biological material and in simple thin carbon films, both of which show better than 5 A resolution. Under such conditions it is possible to examine biological specimens for amplitude images well below the 20 angstrom limit commonly accepted for such preparations. With this very high resolution discrete amplitude images are found in sections after treatment with heavy-metal stain. These amplitude images are as small as 10 angstrom, a size equal to that of lead aggregates, which they may represent.