Methods for the Morphological Study of Tracheal and Bronchial Glands
Joan Gil in Models of Lung Disease, 2020
At the electron microscopic (transmission) level, mucous cells have flat, basal nuclei and lucent granules (300-1800 nm in diameter) and the limiting membranes of many of these granules are fused in human lung. In contrast, serous cells have round, centrally located nuclei and granules (300-1000 nm in diameter) with dense contents, and the membranes of most serous cells are not fused (Meyrick and Reid, 1970) (Figure 7). Although transmission electron microscopy has been used for ultrastructural examination of secretory granules by almost all investigators, Kawada et al. (1981) used scanning electron microscopy (SEM) to observe secretory granules in human bronchial gland using a freeze-fracture method that provides tridimensional images of secretory granules. However, the term electron microscopy used in this chapter refers to transmission electron microscopy by ultrathin sectioning except where stated otherwise.
Unmasking the Illicit Trafficking of Nuclear and Other Radioactive Materials
Michael Pöschl, Leo M. L. Nollet in Radionuclide Concentrations in Food and the Environment, 2006
Transmission electron microscopy (TEM) is capable of higher magnification than SEM and typically has a spatial resolution on the order of 0.1 nm, which allows extremely small structural features to be examined [40,41]. The use of a thin sample cross section enables electrons to be passed through the sample. The resultant images enable the user to observe structural features of the material, such as particle size, porosity, crystal morphology, and the presence of individual grains, stacking faults, twin boundaries, and dislocations. Electron diffraction enables crystal structures to be determined from individual areas of a sample. Information obtained from both imaging and electron diffraction can be used to determine the processing history of materials. This information is highly valuable in providing clues for tracing the source of the material. Excellent examples highlighting the use of the technique to analyze plutonium-bearing samples are detailed in recent review articles [23,42].
Identifying Nanotoxicity at the Cellular Level Using Electron Microscopy
Suresh C. Pillai, Yvonne Lang in Toxicity of Nanomaterials, 2019
Conventionally it is regarded that there are two main types or modes of electron microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). There have been many adaptations of these techniques, the base microscopes and their associated specimen preparations which include low temperature and cryo techniques. To ensure that the specimen is able to withstand the electron beam, various preparatory techniques (Figure 7.1) must be carried out and will be discussed in greater detail in Section 7.3. When gathering three-dimensional (3D) information about a specimen, the microscopist generally employs the SEM, where it is used to visualise the surface topography of a specimen. TEM images are generally two dimensional (2D) in nature but in recent years and with advances in technology, computational power, and software packages a series of 2D TEM images can be collected via electron tomography (ET) and reconstructed to create a 3D model of the structure of interest.
Progress in the development of stabilization strategies for nanocrystal preparations
Published in Drug Delivery, 2021
Jingru Li, Zengming Wang, Hui Zhang, Jing Gao, Aiping Zheng
The sizes and shapes of nanocrystals were analyzed via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In SEM, image results are generated through the interaction between the electron beam and atoms at various depths in the sample. For example, by collecting secondary electrons and backscattered electrons, information about the microstructure of the material can be obtained (Figure 7). In a transmission electron microscope, an image is obtained by capturing transmitted electrons in a sample. The accelerated and clustered electron beam can be transmitted to a very thin sample, and the electrons collide with the atoms in the sample and change direction, thereby generating solid angle scattering, which can be used to observe the ultrastructures of particles, and the resolution can reach 0.1 ∼ 0.2 nm (Figure 8).
Specific ADAM10 inhibitors localize in exosome-like vesicles released by Hodgkin lymphoma and stromal cells and prevent sheddase activity carried to bystander cells
Published in OncoImmunology, 2018
Francesca Tosetti, Roberta Venè, Caterina Camodeca, Elisa Nuti, Armando Rossello, Cristina D'Arrigo, Denise Galante, Nicoletta Ferrari, Alessandro Poggi, Maria Raffaella Zocchi
Transmission electron microscopy. ExoV-containing pellet (50–100μg of protein) was resuspended in 50 to 100 μl of 2% PFA and 5 μl were deposited on Formvar-carbon coated EM grids for 20 min, then transferred to a 50-μl drop of 1% glutaraldehyde for 5 min. Grids were washed 8 times with 100μl drop of distilled water for 2 min and transferred to a 50μl drop of uranyl-oxalate solution, pH 7, for 5 min. Samples were then contrasted in a solution of uranyl oxalate, pH 7, embedded in a mixture of 4% uranyl acetate and 2% methyl cellulose in a ratio of 100μl/900μl, transferred to a 50-μl drop of methyl cellulose-UA for 10 min on ice and air dried. ExoV were observed under a transmission electronic microscope Zeiss Leo EM 900 at 80 kV. For TEM analysis of MSC16412 exposed to gold-conjugated CAM29 (CAM49) overnight at 2.5 µM concentration, cells were processed as described30 (see Supplemental Methods).
Monoclonal glomerulopathy with features of cryoglobulinemic glomerulopathy in murine multiple myeloma model
Published in Ultrastructural Pathology, 2020
Ping L. Zhang, Guillermo A. Herrera, Bei Liu
A Vk*MYC model of myeloma in transgenic mice has been previously reported.21 In the current study, the Vk*MYC transgenic mice and wild-type control littermates were bred and maintained according to the established guidelines and an approved protocol by the Medical University of South Carolina Institutional Animal Care and Use Committee. Six wild-type control littermates and 12 Vk*MYC transgenic mice with myeloma at 50–70 weeks were used for the study. Each mouse kidney was divided into two parts. One part was frozen for immunofluorescent studies. The frozen renal tissue was cut for two-step immunofluorescent stains for kappa, and lambda (1:50 dilution for primary kappa and lambda antibodies, Southern Biotechnology Associates, Birmingham, AL). Immunofluorescent staining evaluation was conducted by two of the authors working independently (PLZ, BL). The other part of each kidney was fixed in 3% of glutaraldehyde, and underwent routine processing for electron microscopy. The tissue for electron microscopy was post-fixed in osmium tetroxide, embedded in resin, sectioned, and stained with Methylene Blue-Azure II for light microscopic survey. Tissue was further thin sectioned and stained with uranyl acetate and lead citrate. The grids for electron microscopy were examined using a transmission electron microscope.
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