Microspectrophotometry

Other X-ray techniques include X-ray diffraction (XRD), which reveals information about crystal structures. It is used less frequently than XRF in forensic science. Other related techniques, such as Auger spectroscopy, have yet to find significant applications in forensic chemistry. 

Microscopes and spectroscopes both use electromagnetic energy to probe matter, so why not use a microsoc as the source of energy so that very small samples such 

The availability of UV/VlS spectrophotometers has revitalized the examination of evidence for characteristics associated with color. Fibers, inks, and paints in particular can be examined nondestructively and characterized by a spectrum as well as the analyst s judgment of their color. Prior to the availability of UV/VIS MSP, obtaining a visible spectrum of a fiber involved destructive extraction followed by colorimetry. Large numbers of fibers were needed, and potentially useful inter- and intrasample variations in color were lost. (Particular applications of MSP to color determinations are addressed in the application chapters that follow.) 

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Laing, D.K. Dudley, R.J. Issacs, M.D.J. Colorimetric Measurements of Small Paint Fragments Using Microspectrophotometry, Forensic Science International. 1980, 16, 159-171. 

Plant cytochemistry/histochemistry continues to evolve as fluorescence microscopy (16-19), confocal fluorescence microscopy (20,21), and microspectrophotometry (22) expand our quantitative knowledge of the distributions of chemical constituents in plant cells and tissues. With regard to microspectrophotometry, this is possible for single cells, as the Arcturus Corporation (Mountain View, C A) has developed an instrument capable of isolating single cells. 

Cherry RJ. New Techniques of Optical Microscopy and Microspectrophotometry, CRC Press, Boca Raton, FL, 1990. 

Kawai H, Nakamura S, Mimuro M, Furuya M, Watanabe M. Microspectrophotometry of the autofluorescent flagellum in phototactic brown algal zoids. Protoplasma 1996 191 172-177. 

Rasmusson, and R. G. Fulcher. Varia- HV048 tion in ferulic acid concentration among diverse barley cultivars measured by HPLC and microspectrophotometry. J Agr Food Chem 1998 ... 

That the DNA content doubles prior to cell division was established by microspectrophotometry. It was clear that both daughter cells must receive one or more identical molecules of DNA. However, it was not known whether the original double-stranded DNA molecule was copied in such a way that an entirely new double-stranded DNA was formed or whether, as we now know to be the case, the two chains of the original molecule separated. The latter is called semiconservative replication, each of the separated strands having a new complementary strand synthesized along it to form the two identical double-stranded molecules. 

Fluorescence microspectrophotometry typically provides chemical information in three modes spectral characterization, constituent mapping in specimens, and kinetic measurements of enzyme systems or photobleaching. All three approaches assist in defining chemical composition and properties in situ and one or all may be incorporated into modem instruments. Software control of monochrometers allows precise analysis of absoiption and/or fluorescence emission characteristics in foods, and routine detailed spectral analysis of large numbers of food elements (e.g., cells, fibers, fat droplets, protein bodies, crystals, etc.) is accomplished easily. The limit to the number of applications is really only that which is imposed by the imagination - there are quite incredible numbers of reagents which are capable of selective fluorescence tagging of food components, and their application is as diverse as the variety of problems in the research laboratory. 

Takabe K, Fukazawa K, Terashima N, Fukushima K (1987) Ligmfication process of hardwoods xylem elements by UV microspectrophotometry Proc 32nd Jpn Lignin Symp, Fukuoka, Japan, 1-4... 

Figure 7. Spatial distribution of oxidation products for PE after 207 and 255 hours of exposure at lOO C in atmospheric air. Points Experimental carbonyl profiles determined by microspectrophotometry. Continuous line kinetic model...

Chemical ionization m.s. Colorimetry Cytofluorometry and microspectrophotometry Enzymic double-isotope method Fluorometry... 

Schindler et al. have published a comprehensive review of the relevant literature and of types and causes of stains formed during production and dyeing and finishing of textiles (see Table 8.19). In this review the fibre-dependent limits of detection by IRS of stains caused by mineral oil and paraffin, sizes based on polyacrylate, fabric softeners and polyester carriers are described. Stains which arise during textile usage are often easier to analyse because the circumstances of their occurrence are mostly known or are fairly easy to determine. lUing-Giintlier and Hanus have described a stain analysis with microspectrophotometry. ... 

Weigmann H D, Steenken I, Moore RAF and Ruetsch S. Analysis of dye hansport phenomena in Hercoseh heated wool hy microspectrophotometry . Proceedings of the 7thIntemationalWoolTextileResearchConference, volumeS. 141-150,Tokyo. 1985. 

Table 1. Survey of the distribution of UV photoreceptors among aquatic organisms. (This list is not all-inclusive.) Microspectrophotometry is... 

K.L. Carlton, F.I. Harosi, T.D. Kocher (2000). Visual pigments of African cichlid fishes evidence for ultraviolet vision from microspectrophotometry and DNA sequences. Vision Res., 40, 879-890. 

Kohen E (1981) Examination of single cells by microspectrophotometry and microspectroflu-orometry. Elsevier-North Holland, New York... 

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