Journal of Electron Microscopy Technique 

About: Journal of Electron Microscopy Technique is an academic journal. The journal publishes majorly in the area(s): Transmission electron microscopy & Electron diffraction. It has an ISSN identifier of 0741-0581. Over the lifetime, 767 publications have been published receiving 15980 citations.

EELS Log-Ratio Technique for Specimen-Thickness Measurement in the TEM

Abstract: We discuss measurement of the local thickness t of a transmission microscope specimen from the log-ratio formula t = lambda ln (It/I0) where It and I0 are the total and zero-loss areas under the electron-energy loss spectrum. We have measured the total inelastic mean free path lambda in 11 materials of varying atomic number Z and have parameterized the results in the form lambda = 106F (E0/Em)/ln (2 beta E0/Em) where F = (1 + E0/1,022)/(1 + E0/511)2, the incident energy E0 is in keV, the spectrum collection semiangle beta is in mrad, and Em = 7.6Z0.36. This formulation should allow absolute thickness to be determined to an accuracy of +/- 20% in most inorganic specimens.

Controlled environment vitrification system: an improved sample preparation technique.

Abstract: The controlled environment vitrification system (CEVS) permits cryofixation of hydrated biological and colloidal dispersions and aggregates from a temperature- and saturation-controlled environment. Otherwise, specimens prepared in an uncontrolled laboratory atmosphere are subject to evaporation and heat transfer, which may introduce artifacts caused by concentration, pH, ionic strength, and temperature changes. Moreover, it is difficult to fix and examine the microstructure of systems at temperatures other than ambient (e.g., biological systems at in vivo conditions and colloidal systems above room temperature). A system has been developed that ensures that a liquid or partially liquid specimen is maintained in its original state while it is being prepared before vitrification and, once prepared, is vitrified with little alteration of its microstructure. A controlled environment is provided within a chamber where temperature and chemical activity of volatile components can be controlled while the specimen is being prepared. The specimen grid is mounted on a plunger, and a synchronous shutter is opened almost simultaneously with the release of the plunger, so that the specimen is propelled abruptly through the shutter opening into a cryogenic bath. We describe the system and its use and illustrate the value of the technique with TEM micrographs of surfactant microstructures in which specimen preparation artifacts were avoided. We also discuss applications to other instruments like SEM, to other techniques like freeze-fracture, and to novel "on the grid" experiments that make it possible to freeze successive instants of dynamic processes such as membrane fusion, chemical reactions, and phase transitions.

Protein A-gold electron microscopic immunocytochemistry: Methods, applications, and limitations

Abstract: The postembedding protein A-gold immunocytochemical approach has been introduced as an alternative to other techniques for the ultrastructural localization of antigenic sites. The present review deals with the development, the theoretical background, and technical approach of the protein A-gold method as well as the different modifications introduced in order to enhance the resolution of the results and to perform double labelings on the same section. Various examples demonstrate the reliability and the wide range of application of this technique. In addition, some problems, pitfalls, and limitations particular to this method are reported.

The preparation of cross‐section specimens for transmission electron microscopy

Abstract: The structure and chemistry of thin solid films are best studied by transmission electron microscopy (TEM) when they are viewed in cross-section—that is, when the surface normal of the film is made perpendicular to the electron beam. In this orientation, the substrate, the thin film layers, and the interfaces between them can be imaged either simultaneously or individually. Further, information from each of these regions remains distinct from that obtained from the others, eliminating the problems of superimposition that are a consequence of viewing a layered structure in the conventional manner (i.e., parallel to the surface normal). A technique for fabricating TEM specimens that can be viewed in cross-section is described here. Although the majority of our work is with silicon-based materials, the technique can be readily adapted to the study of other systems.

Three-dimensional reconstruction of single particles from random and nonrandom tilt series.

Abstract: To overcome the radiation damage-induced limitations to the resolution of three-dimensional reconstructions from electron microscopic tilt series, novel reconstruction schemes have been developed that require only a single exposure of the specimen. The tilt series collected with these methods have random projection directions. First, three-dimensional reconstruction techniques are described that are applicable to data obtained from tilt series with regular tilt geometry, followed by the extensions of these techniques to permit analysis of projection series with randomly spaced tilts. The main emphasis is placed on the weighted back-projection methods, which have recently been extended so as to be applicable to random tilt series. Besides a description of the algorithms, the complete procedure for a threedimensional reconstruction from a single-exposure, random conical tilt series is explained, including the determination of the azimuthal angles, the alignment scheme for conical tilt series, the dependence of the achievable resolution on the number of projections for regular conical and single-axis geometries, and the method to calculate the actual resolution of two-dimensional image averages and of three-dimensional reconstructions using the phase residual and Fourier ring correlation criteria. Examples are given of biological specimens to which these three-dimensional reconstruction methods have been applied.