Ultraviolet microscopes

A confocal microscope using ultraviolet light and a 1.30-NA objective is expected to produce a resolution of about 0.07 p.m (70 nm), but no such instmment has been developed. There are confocal attachments that fit on almost any compound microscope. If one of the eady twentieth century ultraviolet microscopes or a Burch reflected optics scope can be found, the shorter wavelength and improved contrast would make possible better resolution than any compound light microscope. 

It is well known that the structure, distribution and properties of protolignin in cell walls vary according to cell type and morphological location. This is based upon extensive studies on topochemical properties of lignin using various methods such as ultraviolet microscopic photometry (1,2), bromination-SEM-EDXA (3) and other physical or chemical analyses of isolated tissue fractions (4). 

I. Isolated lignin preparations. Tappi 45 826-829 Boutelje JB, Eriksson 1 (1982) A UV-microscopy study of lignin in middle lamella fragments from fibers of mechanical pulp of spruce. Sven Papperstidn 85 R39-R42 Boutelje JB, Jonsson U (1980) Ultraviolet microscope photometry of pulp fibers. UV-absorbance and its relationship to chlorine number, kapp number and lignin content. Cellul Chem Technol 14 53-67... 

In recent years, serological techniques have been developed for identifying and enumerating wild yeasts in the presence of culture yeast (see Chapter 16) [92, 93]. It is now possible by fluorescent antisera to detect under an ultraviolet microscope certain wild yeasts (including those in the genus Saccharomyces) at levels as low as one cell per 10 culture yeasts. 

When a labeled precursor of protein or RNA is injected, all the cells of the marrow are labeled because RNA and protein are synthesized during interphase. But the rate of RNA synthesis decreases as the cell matures. Furthermore, staining with basophilic dyes reveals a progressive decrease in basophilia, which indicates that the RNA content of the cell decreases as the cell matures. This finding is supported by observations made with the ultraviolet microscope. 

Alan Franklin ARPA) Your problem of hydrolysis or oxidation of calcium fluoride is a serious one. You can get appreciable oxidation sufficient, for instance, to control the effect of the mobility of the fluoride even though you cannot see any damage to the surface. If one looks through an ultraviolet microscope in the region of 200 m//, which is very sensitive to the oxygen, you can more sensitively detect whether or not there is oxygen present. 

F.F. Lukas, M.B. Stark, A study of living sperm cells of certain grasshoppers by means of the ultraviolet microscope. J. Morphol. 52, 91-113 (1931)... 

Microscopy (qv) plays a key role in examining trace evidence owing to the small size of the evidence and a desire to use nondestmctive testing (qv) techniques whenever possible. Polarizing light microscopy (43,44) is a method of choice for crystalline materials. Microscopy and microchemical analysis techniques (45,46) work well on small samples, are relatively nondestmctive, and are fast. Evidence such as sod, minerals, synthetic fibers, explosive debris, foodstuff, cosmetics (qv), and the like, lend themselves to this technique as do comparison microscopy, refractive index, and density comparisons with known specimens. Other microscopic procedures involving infrared, visible, and ultraviolet spectroscopy (qv) also are used to examine many types of trace evidence. 

Microscopes are also classified by the type of information they present size, shape, transparency, crystallinity, color, anisotropy, refractive indices and dispersion, elemental analyses, and duorescence, as well as infrared, visible, or ultraviolet absorption frequencies, etc. One or more of these microscopes are used in every area of the physical sciences, ie, biology, chemistry, and physics, and also in their subsciences, mineralogy, histology, cytology, pathology, metallography, etc. 

Additions to the PLM include monochromatic filters or a monochromator to obtain dispersion data (eg, the variation in refractive index with wavelength). By the middle of the twentieth century, ultraviolet and infrared radiation were used to increase the identification parameters. In 1995 the FTIR microscope gives a view of the sample and an infrared absorption pattern on selected 100-p.m areas (about 2—5-ng samples) (37). 

When fabricated polycarbonate parts are exposed to ultraviolet light, either in laboratory equipment or by outdoor exposure, a progressive dulling is observed on the exposed surface. The dullness is due to microscopic cracks on the surface of the resin. If the surface resin is analysed it is observed that it has a significantly lower molecular weight than the parent polymer. 

Filthy conditions, due to rodent or insect population, may be observed in a grain warehouse. The inspector notes rat-chewed flour sacks and sacks contaminated with rat excrement. He removes a sample of sacking and flour from such contaminated areas and submits them to the analyst. Urine fluoresces under ultraviolet light. Where rodent urine is to be confirmed, the xanthydrol test is one of several that may be used. Excreta pellets may be moistened with water or an appropriate clearing solution and crushed for observation under the compound microscope. The presence of striated hair fragments indicates rodent excrement. 

Indirect immunofluorescence assay (IFA) A laboratory test used to detect antibodies in serum or other body fluid. The specific antibodies are labeled with a compound that will make them glow a fluorescent green color when observed microscopically under ultraviolet light. 

Chemical fixation for transmission electron microscopy prepares cells for the preservation of damage due to subsequent washing with aqueous solvents, dehydration with organic solvents such as ethanol or acetone, embedding in plastic resins, polymerization of the resins by heat, exothermic catalysts, or ultraviolet radiation, and imaging with high-energy electron beams in an electron microscope. 

In luminescent microscope, light from the ultraviolet source (UV source) excites the fluorescence of the object, the luminescent image might be catched... 

An instrument used for obtaining magnified images of small objects. For illumination of the object microscopes may use ordinary light, ultraviolet light or a beam of electrons. See Electron Microscope. 

The identification of ivory and ivory substitutes is based on the (55) physical and chemical class characteristics of these materials. A common approach to identification is to use the macroscopic and microscopic physical characteristics of ivory in combination with a simple chemical test using ultraviolet light. 

The sample is usually ablated using a Nd-YAG ultraviolet laser (k = 266 nm the theory of laser light is given in Section 4.1). Earlier systems used an infrared laser, but chemical fractionation was found to be a problem (Jeffries et al. 1996). A movable stage and integral optical microscope allow... 

Xiong F, Komenda J, Kopecky J, Nedbal L (1997) Strategies of ultraviolet-B protection in microscopic algae. Physiol Plant 100 378-38... 

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