Light microscopy specimen preparation

See also Air Analysis Sampling. Microscopy Applications Environmental. Microscopy Techniques Light Microscopy Specimen Preparation for Electron Microscopy Scanning Electron Microscopy. Surface Analysis Low... 

Specimen preparation may be broadly classified into two main areas specimen preparation techniques for transmitted-light microscopy (thin sections, smears, fibers, particulate strews) and specimen preparation techniques for reflected-light microscopy (surface preparation of opaque and nearly opaque materials). However, they are by no means exclusive and, although metals, ores, and opaque minerals may be studied by reflected light only, thin sections, smears, etc., may be studied both by transmitted and by reflected light, e.g., transmitted-light and epifluorescence microscopy. The advantages of such dual observational techniques relate in particular to contrast enhancement (criterion (3)). 

Body fluid specimens will be prepared and stained and the morphologic characteristic of the cells and the environment in which these cells are found will be examined by light microscopy. To achieve this, a representative cell sample must be obtained and adequate cell fixation is a prerequisite. Proper identification of the specimen and protection of the specimen s integrity are essential. Finally, pertinent patient clinical history is important for accurate specimen interpretation. 

Moran DT, Rowley JC. Biological specimen preparation for correlative light and electron microscopy, in Correlative Microscopy in Biology, Instrumentation and Methods (Hayat MA, ed.), Academic Press, New York, 1987, pp. 2-22. 

Light Microscopy. Although films of the terpolymer were birefrin-gent, no spherulites could be detected regardless of the manner in which specimens were prepared. Samples cast from a 2% solution in tetra-hydrofuran (THF) and annealed at 60 °C overnight had optical melting points which ranged from 63° to 75°C. 

The microstructure of a material can only be viewed in a light microscope after a specimen has been properly prepared. Metallurgists have developed extensive techniques and accumulated knowledge of metal specimen preparations for over a century. In principle, we can use these techniques to examine not only metallic materials but also ceramics and polymers in practice, certain modifications are needed and a certain degree of caution must be exercised. The main steps of specimen preparation for light microscopy include the following. 

Ultramicrotomy is basically the same type of method as microtomy for preparing soft specimens for light microscopy. However, ultramicrotomy can be used to section a specimen to the 100 nm scale. It is commonly used to prepare polymeric or biological TEM specimens. 

Compare light microscopy, transmission electron and scanning electron microscopy in terms of optical arrangement, illumination source, working environment, imaging formation mechanism and specimen preparation discuss their similarities and differences. 

Interfacing Light Microscopy with TEM Fixation and Specimen Preparation for TEM Selective Staining of Nuclear Components Image Analysis and Enhancement Three-Dimensional Reconstructions by TEM... 

In contrast to specimens that were not prepared by extrusion or injection molding but were heated and pressed without appreciable shear stress, there is no significant contrast of the LC-poor and LC-rich phases in SEM of broken samples. This is true, independent of the composition. The existence of different phases, however, can be shown with polarized light microscopy (see below). 

Conventional methods used for the preparation of biological material both for light microscopy and EM consist of fixation, dehydration, and embedding. These procedures result in increased permeability of the cell membrane with resultant loss or redistribution of mobile intracellular elements. Sections are then stained, resulting in the deposition of elements onto the specimen so that the resultant spectrum is not representative of the elemental composition in vivo (Figure 2). In consequence, such preparation methods are rarely used when the specimen is intended from the outset for microanalysis. 

See also-. Chiroptical Analysis. Microscopy Overview. Microscopy Techniques Specimen Preparation for Light. Optical Spectroscopy Refractometry and Reflectometry. Particle Size Analysis. 

The objective of specimen preparation for light microscopy is to allow the structures of materials (biological and nonbiological) to be revealed with sufficient contrast, and features of interest to be described, recorded, and characterized, at a fineness of scale beyond the visual acuity of the naked eye. The fineness of scale is ultimately limited by the limit of resolution (resolving power) of the microscope imaging system. 

Specimen Preparation. A number of methods are used to prepare specimens for electron microscopy. Because electron microscopy is much more powerful than traditional light microscopy, the... 

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