Transmission electron microscopy with Zernike phase plate.
The possibility of implementing a Zernike phase plate in a transmission electron microscope is investigated both theoretically and experimentally. The phase-retarding plate in the form of thin film with a hole in the center is positioned in the back-focal plane of the objective lens. The experiments show that the phase plate functions as predicted, producing a cosine-type phase contrast transfer function. Images of negatively stained horse spleen ferritin were highly improved in the contrast and the image-modulation, compared to those acquired without the phase plate. Charging and related difficulties were encountered during the phase plate experiments. In order to make the technique user-friendly a number of improvements have to be made, and are discussed in terms of the current level of technology and instrumentation.
Danev
R
R
National Institute for Physiological Sciences, Okazaki National Research Institutes, Japan.
Nagayama
K
K
D000818:Animals; D005293:Ferritins / Q000032:analysis / Q000648:ultrastructure; D006736:Horses; D008854:Microscopy, Electron / Q000295:instrumentation; D008858:Microscopy, Phase-Contrast; D013154:Spleen / Q000737:chemistry / Q000648:ultrastructure
D005293:Ferritins