Ultra-thin sections

Fig. 10.2. Immunogold staining of an ultra-thin section of an immature Acanthocheilonema viteae uterine mf with mAb 24-4. Note that A. viteae chitinase is present in the cuticle (arrowheads), but not on the surface. (Photograph W. Rudin.)...

In order to observe a structure inside a bulk sample with TEM, one should prepare a replica of the fracture surface of the sample, or must make an ultra-thin section whose thickness is small enough for electron beams to pass through the section. Unfortunately, however, orientation of crystallites might be changed by microtoming. 

Roth, J. (1982) The preparation of protein A-gold complexes with 3 nm and 15 nm gold particles and their use in labeling multiple antigens on ultra-thin sections. Histochem. J. 14,791-801. 

Morphology of select star blocks was investigated by transmission electron microscopy (TEM). Films were cast from toluene and annealed for 2 days at 120 °C. Ultra thin sections (-50 nm) of unstained samples were cut by cryogenic microtome techniques. Samples were viewed by a JOEL (JEM-1200EXII) TEM. 

In previous literature, the type B hysteresis was ascribed to a lamellar-like structure that commonly observed in the pillared materials.[13,14] Here its existence in our mesoporous materials is associated with some internal defects in the channels. To further understand such hysteresis behavior, we compared the microtomed ultra-thin sections TEM micrographs of these two samples. In Fig. 2A, B, we show the typical parallel channels of MCM-41 and the well-ordered hexagonal mesoporous in pure silica sample(I). However in Fig. 2 C, D, one can obviously find the aluminosilicate(II) possessing the normal well-aligned MCM-41 nanochannels with extensive voids interspersed. The white void parts were attributed to the structural defects. These structural defects are not the lamellar form but the irregularly shaped defects. The size of the defects is not uniform and distributes between 5.0-30.0 nm. nanometers. Therefore, these aluminosilicate mesoporous materials were composed of structural defects-within-well-ordered hexagonal nanochannels matrix. 

Pedemonte et have studied by low-angle X-ray diffraction and electron microscopy (on ultra-thin sections of the bulk material) a SIS copolymer containing... 

Electron Microscopy. Figure 3 shows electron micrographs of ultra-thin sections of film specimens of the three kinds of block copolymers. As can be seen in the figure, TR-41-1647 and TR-41-1648 specimens have a heterogeneous structure in which the polystyrene domains are dispersed within a polybutadiene matrix and are connected to each other to form a swirl-like structure. On the other hand, TR-41-1649 specimen is seen to consist of alternating lamellar domains of the two components. Changes of the domain structure with fractional compositions of styrene and butadiene components are consistent with predictions of the current theories of micro-phase separation (12,13,14,15) for block copolymers cast from such a nearly nonselective solvent as the mixture of THF and methylethylketon (90/10 in volume ratio). 

Figure 25.7 TEM of rubber-modified (36%) injection moulded S/DPE(15) (a) MSP 1, (b) MSP 2, and (c) MSP 3. Cryo ultra thin sections stained with Ru04...

Figure 25.8 TEM of 36 % MSP 1 rubber, mixed in S/DPE(30) and injection moulded. Cryo ultra thin section stained with RUO4...

Figure 25.14 TEM of crazes in S/DPE(15) modified with emulsion polymerized rubber. Cryo ultra thin section stained with 0s04/Ru04...

Figure 25.18 TEM of crazes in S/DPE(30) modified with S - BH S rubber. Cryo ultra thin sections stained with OSO4/RUO4...

Figure 1. Ultra thin section of Oxalis acetossa showing numerous short chain phytoplasma in the infected phloem tissues observed by Transmission Electron Microscopy.

Ultra-thin sections (gold-silver) are cut using a diamond knife (Dupont Company) and ultramicrotome (Reichert Ultracut E, Austria), and the sections are contrasted with uranyl acetate and lead citrate (26) and examined with a JEOL (JEMlOlO) transmission electron microscope. 

B22. Brenner, M., and Niederwieser, A., Ultra thin section chromatography of amino acids. Experientia 16, 378-383 (1960). 

Lucocq reviewed the methods of absolute antigen quantitation in cellular structures in ultra-thin sections with colloidal gold. The absolute antigen quantitation is based on a knowledge of the relationship between the number of gold particles and the number of antigens (which is expressed as the labelling efficiency, LE). 

Note A well made polished, ultra thin section, allowing the combination of transmitted- and reflected-light observations, sometimes simultaneously, is probably the best method for all phases, particularly for fly ash. quarry rocks, and clinkers. 

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