Electron microscopy mounting

This technique can be applied to samples prepared for study by scanning electron microscopy (SEM). When subject to impact by electrons, atoms emit characteristic X-ray line spectra, which are almost completely independent of the physical or chemical state of the specimen (Reed, 1973). To analyse samples, they are prepared as required for SEM, that is they are mounted on an appropriate holder, sputter coated to provide an electrically conductive surface, generally using gold, and then examined under high vacuum. The electron beam is focussed to impinge upon a selected spot on the surface of the specimen and the resulting X-ray spectrum is analysed. 

Hasle G, Fryxell, G. Diatoms cleaning and mounting for light and electron microscopy. Trans Am Microscopical Soc 1970 89 435 468. 

Small viruses, bacterial flagella, ribosomes, and even molecules can be seen by electron microscopy. However, to obtain a clear image in three dimensions requires a computer-based technique of image reconstruction or electron microscope tomography, which was developed initially by Aaron Klug and associates.344-349 A sample is mounted on a goniometer, a device that allows an object to be tilted at exact angles. Electron... 

Crystal reaction study mechanistic tools, 296 computer simulation, 297 electronic spectroscopy, 298 electron microscopy, 298 electron paramagnetic resonance (EPR), 299 nuclear magnetic resonance (NMR), 298 Raman spectroscopy, 299 Crystal reaction study techniques crystal mounting, 308 decomposition limiting, 309 polarized IR spectroscopy, 309 temperature control, 308 Cycloreversions, adiabatic photochemical involving anthracenes, 203 excited state properties of lepidopterenes, 206... 

Catalyst surface areas were measured using the multi-point BET method on a Carlo-Erba Ins. Sorpty 1750. Before the measurements, the samples were heated under dynamic vacuum at 573 K for 1 h in order to remove adsorbed water and impurities. Measurements were made at liquid nitrogen temperature with nitrogen as the adsorbate gas. Powder X-ray diffraction measurements were performed on a Siemens Model D-500 diffractometer with Co Kc monochromatic radiation (X = 1.78901 A) and the high resolution electron microscopy was carried out on a Topcon EM-002B microscope. To prevent artefacts no solvents were used in the preparation and mounting of samples for HRTEM. 

Microscopy. Scanning electron microscopy was run on resin samples using a AMR 1200 Scanning Electron Microscope. The samples were mounted on the stub using double stick tape and then sputter coated with gold. 

Fig. 12.7. Scanning electron microscopy reveals details of hair fibers. Normal hairs from an adult C57BL/6J examined as a whole mount (A) illustrates density of mouse hairs and the nature of the normal skin surface. Manually plucked hairs illustrate the structural differences between some of the hair fiber types (B). Higher magnification of boxed area in B reveals the regular cuticular scale patterns on these hair fibers (C). These approaches illustrate details of hair fiber structure and density (80).

In electron microscopy, a beam of electrons is focused using electromagnetic lenses. The specimen is mounted within a vacuum so that the electrons are not absorbed by atoms in the air. 

In contrast with light microscopy where optical lenses focus a beam of light, in electron microscopy electromagnetic lenses focus a beam of electrons. Because electrons are absorbed by atoms in the air, the specimen has to be mounted in a vacuum within an evacuated tube. The resolution of the electron microscope with biological materials is at best 0.10 nm. 

Samples of microspheres were mounted on aluminum specimen mounts by means of double-faced tapes. The microspheres were fractured with razor blades to expose the internal matrix. The samples were then coated with approximately 125 of gold by pulsing the sputter coater to avoid the possibility of artifact caused by heat generation. Secondary emissive scanning electron microscopy was performed with an Amray 1600 Turbo scanning electron microscope. 

Two types of samples were prepared for detailed morphological examination. Sections of the as-polymerized material were examined directly by WAXS and DSC. Samples also were prepared by casting films from a solution of the polymer in dimethyl formamide (DMF) at 52°C. Solvent was allowed to slowly evaporate, and the films were dried by annealing for 670 hr at 52°C, followed by slow cooling to room temperature. Thin films suitable for electron microscopy were cast from 0.5 wt % polymer in DMF onto clean glass slides, and after 20 hr of annealing at 52°C, floated off on distilled water and mounted on 300-mesh copper grids. 

Ultrathin sections for electron microscopy (thickness approximately 100 nm) must be able to withstand the electron beam and the vacuum in the microscope. For this, it is first necessary to stabilize the ultrastructure of the fresh tissue by fixation, then to dehydrate it with an organic solvent, and finally to embed it in a resin. The resulting hard block can be cut into ultrathin sections, which are then mounted on a grid and stained. For immunogold labeling, free-aldehyde groups and nonspecific binding sites... 

Single small samples representative of each distinguishing feature from each object were cut and mounted for scanning electron microscopy. Each was carbon coated, and X-ray microanalysis [energy dispersive spectroscopy (EDS)]... 

In addition, two samples were cut and mounted on stubs for scanning electron microscopy. One sample was selected from a location near the blade edge and contained more than one fiber pseudomorph. The second sample, without pseudomorphs, was cut from the reverse side of the blade for comparative purposes. 

Equilibrium fluid cracking catalysts were obtained from several U.S. refineries. Scanning electron microscopy (SEM) studies were performed on these materials by mounting all equilibrium FCC s onto indium foil without coating the samples in an AMRAY model 1810 D SEM. 

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