Visualization techniques electron microscopy

Immunoelectron microscopy (IEM) is the term generally used for techniques that detect the specific binding of antibody to antigen that can be visualized by electron microscopy (1). The use of these techniques results in a 2- to 10,000-fold increase in particle numbers in comparison with methods not using antisera (1) and allows the transmission electron microscope (TEM) to become a sensitive tool, which the plant virus diagnostician or researcher can use to... 

Isolation in cell culture and direct visualization by electron microscopy, followed by immunological identification using immunohistochemical techniques, may help if the identity of the VHP agent is unknown. In addition, immunohistochemical techniques, using formalin-fixed tissues, can retrospectively identify specific viral antigens using batteries of specific immune sera and monoclonal antibodies (48). 

Scanning electron microscopy is commonly used to study the particle morphology of pharmaceutical materials. Its use is somewhat limited because the information obtained is visual and descriptive, but usually not quantitative. When the scanning electron microscope is used in conjunction with other techniques, however, it becomes a powerful characterization tool for pharmaceutical materials. 

There are three potential methods by which a protein s three-dimensional structure can be visualized X-ray diffraction, NMR and electron microscopy. The latter method reveals structural information at low resolution, giving little or no atomic detail. It is used mainly to obtain the gross three-dimensional shape of very large (multi-polypeptide) proteins, or of protein aggregates such as the outer viral caspid. X-ray diffraction and NMR are the techniques most widely used to obtain high-resolution protein structural information, and details of both the principles and practice of these techniques may be sourced from selected references provided at the end of this chapter. The experimentally determined three-dimensional structures of some polypeptides are presented in Figure 2.8. 

Dark field Visualization technique for ashes produced by microincineration and fluorescence microscopy useful for low-contrast subjects Electron systems imaging EM shadowing Detection, localization, and quantitation of light elements Structural information from ordered arrays of macromolecules... 

Scanning electron microscopy (SEM) techniques have proven to be suitable for the visualization of block copolymer micelles, as illustrated in, e.g., the recent work of Erhardt et al. on Janus micelles (Sect. 7.3) [55]. 

Due to the high magnification power of the electron microscope, the microstructure of liquid crystals can be visualized. However, aqueous samples do not survive the high vacuum of an electron microscope without loss of water and thus change of the microstructure. Therefore, special techniques of sample preparation are necessary prior to the electron microscopy. Freeze fractme has proved to be successful (Fig. 8),... 

Mieroscopic visualization techniques have also been used to investigate mucus-polymer interactions [36-39]. Transmission electron microscopy was used by Fiebrig et al. [36], whereas different microscopical techniques were used by Lehr et al. [37] for the visualization of mucoadhesive interfaces. Transmission electron microscopy in combination with near-fleld Fourier transform infrared microscopy (FT-IR) has been shown to be suitable for investigating the adhesion-promoting effect of polyethyleneglycol added in a hydrogel [38]. Moreover, scanning force microscopy may be a valuable approaeh to obtain information on mueoadhesion and specific adhesion phenomena [39]. 

Perhaps one obvious technique for evaluating pore structure is electron microscopy, and indeed numerous papers have been pubhshed showing visually attractive scanning electron micrographs (SEM). In fact these studies seldom provide... 

The terminal complex hypothesis proposes that structural manifestations of the cellulose synthase enzyme complex can be visualized with the freeze fracture specimen preparation technique for electron microscopy. These... 

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