Electron microscopic procedure

The dehydration, embedding, and sectioning of pre-embedding electron microscopic immunocytochemistry blocks follow the standard electron microscopic procedures. However, for section staining, the time is reduced to 2-3 min to preserve the size of the silver particles. 

Hamilton and Lone applied a scanning electron microscopic procedure to understand this phenomenon [15]. Electron micrographs of razor-shaved individuals revealed frank skin cuts, the clipping of hair produced less skin trauma, and depilatory agents caused no injury to the skin. The increased infection rates observed were likely the result of compromise to the natural barrier function of the skin. 

Different coals have been observed in the electron microscope when two pore-size ranges appear, one of >20 nm and the other <10 nm (52). Fine pores from 1—10 nm across have been observed using a lead impregnation procedure (53). Effectiveness of coal conversion processes depends on rapid... 

Membrane Characterization The two important characteristics of a UF membrane are its permeability and its retention characteristics. Ultrafiltration membranes contain pores too small to be tested by bubble point. Direc t microscopic observation of the surface is difficult and unreliable. The pores, especially the smaller ones, usually close when samples are dried for the electron microscope. Critical-point drying of a membrane (replacing the water with a flmd which can be removed at its critical point) is utihzed even though this procedure has complications of its own it has been used to produce a Few good pictures. 

A procedure for proplnts is presented by J.W. French (Ref 27), who used both OM and EM (electron microscope) to study plastisol NC curing. He found that the cure time of plastisol NC is a logarithmic function of temp, and direct functions of chemical compn and total available surface area, as well as of particle size distribution. It should be noted that extensive use of statistics is required as a time-saving means of interpreting particle size distribution data. The current state-of-the-art utilizes computer techniques to perform this function, and in addition, to obtain crystal morphology data (Ref 62)... 

Replication avoids the problem of sample deterioration in the instrument, but it is destructive in that reaction of the material cannot be continued after the replica has been prepared. Transitory features cannot be detected unless a series of preparations are examined corresponding to increasing progress of the reaction considered. The textures of replicas have been shown [220] to be in satisfactory agreement with those of the original surface as viewed in the scanning electron microscope. The uses and interpretations of observations made through sample replication procedures are illustrated in the studies of decomposition of metal carboxyl-ates by Brown and co-workers [97,221—223]. 

FIGURE 19.2 Procedure for three-dimensional-transmission electron microscopic (3D-TEM) observation, composed of TEM measurements and computerized tomography to reconstruct a 3D image. (From Kohjiya, S., Kato, A., Shimanuki, J., Hasegawa, T., and Ikeda, Y., Polymer, 46, 4440, 2005. With permission.)... 

First of all, only the samples, prepared according to the procedure (a) were suitable for scanning electron microscope (SEM) measurements. All other samples were very un-... 

The Fe-B nanocomposite was synthesized by the so-called pillaring technique using layered bentonite clay as the starting material. The detailed procedures were described in our previous study [4]. X-ray diffraction (XRD) analysis revealed that the Fe-B nanocomposite mainly consists of Fc203 (hematite) and Si02 (quartz). The bulk Fe concentration of the Fe-B nanocomposite measured by a JOEL X-ray Reflective Fluorescence spectrometer (Model JSX 3201Z) is 31.8%. The Fe surface atomic concentration of Fe-B nanocomposite determined by an X-ray photoelectron spectrometer (Model PHI5600) is 12.25 (at%). The BET specific surface area is 280 m /g. The particle size determined by a transmission electron microscope (JOEL 2010) is from 20 to 200 nm. 

The procedure for the formation of vesicles from this prepolymerized lipid was similar to that for the monomeric lipid. However, the concentration of the lipid in this system was lower than in the case of the monomeric lipid. Also the time of sonication for this polymerized lipid was longer than that for the monomeric lipid because of the decreased freedom of motion of the amphiphilic structure in the polymerized system. The electron microscope pictures (Figure 7) show the formation of tiny and very homogeneous vesicles. 

The peculiarities in the morphology of gels prepared by the one-stage procedure are obvious from Figure 3.8 representing pictures taken with a scanning electron microscope (SEM). One can see a cross-linked network from fibrils and spherical... 

Martinez-Ramon, A., Knecht, E., Rubio, V., and Grisolia, S. (1990) Levels of carbamoyl phosphate synthetase I in livers of young and old rats assessed by activity and immunoassays and by electron microscopic immunogold procedures. J. Histochem. Cytochem. 38, 371-376. 

Home RW, Pasquali-Ronchetti I. A negative staining carbon film technique for studying vimses in the electron microscope. I. Preparative procedure for examining icosahedral and filamentous viruses. J Ultrastructure Res 1974 47 361-383. 

Negata T. Electron microscope radioautography with cryo-fixation and dry mounting procedure. Acta Histochim Cytochem 1994 27 471 —489. 

Because disrupted tissue preparations were unsatisfactory, attempts were made to work either with more organized systems such as tissue slices (liver-Krebs) or to identify and isolate the intracellular organelles involved in the reactions. Cytochemical procedures were developed in the 1930s and 1940s to locate sites of reaction in situ in cells (Chapter 9). Examination of cell ultrastructure became possible when the electron microscope was introduced after 1945. Techniques for the isolation of cell organelles, notably mitochondria, were developed about this time (Chapter 9). 

Electron microscopic examination of midge microsomes prepared by a slightly different procedure than Table VIII revealed a homogeneous mixture of vesicles derived from rough and smooth endoplasmic reticulum, ribosomes and a few mitochondria. Midge preparations are similar in composition to microsomal fractions of southern armyworm fat body and gut (44). 

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