Electron Microscopy EM Methods

The surface area of PSs can be measured by means of quantitative electron microscopy (EM) [49-51], knowing the sizes of particles and pores [51,52], wetting heat [7,53] measurements, etc. But, the most universal methods are based on adsorption measurements [51,53-55], corresponding to the traditional methods of pore size distribution measurements in the range 0.3 to 100 nm. 

When microtubules were visualized by electron microscopy (EM), after the improvement of methods of fixation, it was realized that they formed the structural basis of flagellar axonemes and of so-called spindle fibers, as well as occurring as individual filaments in the cytoplasm. Their designation as part of the cytoskeleton suggested that they acted mainly as fixed structural supports. Subsequent research has focused more and more on their dynamic behavior and on their role as tracks for motor proteins, which may, for example, transport chromosomes during cell division. Microtubules are found in all eukaryotic cells and are essential for many cellular functions, such as motility, morphogenesis, intracellular transport, and cell division. It is that dynamic behavior that allows microtubules to fulfill all of these functions in specific places and at appropriate times in the cell cycle. 

Final and definite proof that indeed vesicles are formed after the one step method and that they still exist after sonication can be established by observing the morphology of the arsonoliposome dispersions using different types of electron microscopy (EM), as discussed elsewhere (9-12). Additionally, the ability of the vesicles to encapsulate aqueous soluble markers as carboxyfluorescein or calcein (see below) serves as proof that vesicular structures are present in most of the arsonoliposome dispersions prepared. 

Another method which requires little protein is electron microscopy (EM), which has long been the tool of choice for the characterization of cell organelles and... 

There are a number of experimental methods, mainly based on XRD and electron microscopy (EM) that can be used to explore the character of crystals. However, different techniques, although nominally measuring the same parameter, measure different things. Further, differences between techniques can be accentuated by characteristics of the crystals, for example, very anisotropic dimensions. For these reasons, the main experimental methods are reviewed prior to discussing results. This section concludes with a summary. 

Using electron microscopy(EM), we can solve three dimensional structures of micro-and meso-porous materials through newly developed methods based on electron ciystallography. The underlying principle among diffraction, image and Fourier transformation for the methods, and a resolution of the method are discussed in terms of structure details we are interested in. An example of structure analysis for SBA-6 shows power of the methods, and future tasks will be discussed at the Conference. 

A method is described that allows the attachment of COPI vesicles and Golgi membranes to glass slides that can then be analyzed using electron microscopy (EM) and immuno-EM methods. Subpopulations of COPI vesicles can be bound selectively using recombinant golgins. Alternatively, COPI vesicles can be attached to prebound Golgi membranes. Marking these vesicles selectively with biotin allows their site of attachment to be identified. 

The various topologies of DNA (supercoiled, circular, linear) can be discriminated by various methods such as electrophoresis and by microscopy techniques such as electron microscopy (EM) [36], cryogenic transmission electron microscopy (cryo-TEM) [37], and atomic force microscopy (AFM) [38]. 

There are two methods to study the morphological properties of electrospun CNT-polymer composite one is electron microscopy (EM) and the second one is atomic force microscopy (AFM). As mentioned earlier, the final morphologies of the electrospun CNT-polymer composite fibers can be affected by several characteristics of the initial solution such as solution concentration, CNT weight fraction, viscosity, surface tension and conductivity of solution in addition to some electrospiiming process (applied voltage, spinning distance, volume flow rate, and the strength of the applied electric field) and environmental conditions (temperature and humidity). 

The biological samples studied by AFM only need little prior biochemical treatment. In contrast, most other methods available nowadays to study membrane proteins at high resolution, that is, three-dimensional (3D) X-ray crystallography and electron microscopy (EM), require extensive pretreatments of the samples, such as solubilization, purification, or fixation, drying, freezing and/or metal coating these may cause to different extents artifacts to the samples. 

To obtain real-space information about the morphology of polymeric materials, various optical microscopic methods such as OM and CLSM are available (cfr. Chp. 5.3). Use of electrons as a light source for microscopy opens other perspectives [124]. Electron microscopy (EM) provides structural information in both the real and reciprocal space. Electron... 

The optical observations cannot resolve the crystalline-amorphous structure. Observation of the crystallites requires methods that provide an analysis in the 10-100 nm range. Electron microscopy (EM) and atomic force microscopy (AFM) are particularly suited for this purpose. Figure 5.4 shows as one example the surface of a partially crystalline polyethylene (PE), as it becomes reproduced in the electron microscope when using a carbon film replica technique. The picture of the surface resembles a landscape with many terraces. These obviously result from cuts through stacks of laterally extended, slightly curved crystalline lamellae, which have thicknesses in the order of 10 nm. 

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