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Assay in biological systems

The bioeompatible potentiometric ion sensors have been successfully applied for ion assay in biological systems such as human blood. They might be used in in-vivo cation assay in biological systems such as intra-arterial assay in the near future. [Pg.607]

More recently we have studied the effects of j3-thia-proline on protein synthesizing systems(56). -Thiapro-line,first synthesized by Eourneau et al. (57) ilia-S not been assayed in biological systems. We have obtained preliminary data indicating that it is a substrate for hog kidney D-aminoacid oxidase and for rat liver mitochondria proline oxidase,two enzymes active on y-thiaproline. [Pg.339]

Pt/Ir alloy coated with a three-layered membrane A 0.2 nM-1 pM Nitric oxide-selective electrode was found to be applicable to real-time nitric oxide assay in biological systems 158... [Pg.386]

The extremely low levels of vitamin D and its metaboUtes in biological systems make it very difficult to assay these products by traditional methods. ... [Pg.133]

The oxidation reactions of luminol and lucigenin can be used to assay for H Oj. For example, analysis of glucose in biological systems can be achieved using a three-enzyme system of mutarotase, glucose oxidase and horseradish peroxidase by correlation with the amount of HjOj released. Similarly, cholesterol can be measured using cholesterol oxidase. The fact that the rate of luminol oxidation depends on the concentration of the catalyst can be used as a method for determination of Co +, Fe +, Cr + and Mn + and other catalysts.Some examples of the use of luminol, isolumi-nol and their derivatives in immunoassays are shown in Table 3.11. ... [Pg.216]

Two fluorescent probes dihydroethidium (DHE) and dichlorodihydrofluorescein (DCFH) are used for superoxide detection in biological systems [54]. Both assays are subjected to some drawbacks such as the oxidation of cytochrome c, the dismutation of superoxide in the presence of DHE [79], and the interaction of DCFH with hydrogen peroxide, hydroperoxides, or peroxynitrite. Particularly big enhancement of DCF formation due to the oxidation of cytochrome c is observed when cytochrome is released from mitochondria during cell death... [Pg.971]

M. Wendeler, H. Reiiaender, J. Hoernschemeyer, G. Schwarzmann, T. Kolter, K. Sandhoff, Recombinant Ganglioside GM2-Synthase - Expression in Insect Cells and Enzyme Assay, Y. C. Lee, R. T. Lee, eds., Methods in Enzymology Recognition of Carbohydrates in Biological Systems, submitted for publication. [Pg.60]

A variety of ATPase activities are present in biological systems. This assay is novel in that it uses hydrophilic interaction chromatography to measure release of labeled 32P from [y-32P ATP. [Pg.348]

The extremely low levels of vitamin ID and its metabolites in biological systems make it very difficult to assay these products by traditional methods. Calcium-binding protein is not found in the intestinal mucosa of vitamin D-deficient animals. It is synthesized only in response to the presence of a material with vitamin D activity. Thus, using antiserum specific to intestinal calcium-binding protein, a radioimmunodiffiision assay (98) conducted on homogenates of intestinal mucosa of chicks fed the test material for 7—10 d allows assay of the material for vitamin D activity down to 1—200 lU. The... [Pg.133]

Fsacting triamcinolone and other 16a, 17a, 21-trihydroxy-20 ketones with phenylhydra-zine in the presence of sulfuric acid (Porter-Silber test) gives a response of less than 10% of the chromogen formation of non-16a-hydroxylated analogs and therefore renders useless this assay so popular for the determination of 17a-corticosteroids in biological systems. [Pg.387]

Webb MR (1992) A continuous spectrophoto-metric assay for inorganic phosphate and for measuring phosphate release kinetics in biological systems. Proc Natl Acad Sci U S A 89 4884-4887... [Pg.24]

A second commonly used approach employs synthetic substrates for spectrophotometric or fluorometric assays [3,4]. These substrates permit a continual assay well suited for kinetic studies and provide reasonable sensitivity. The major drawback is that the substrates are not natural substrates and as such, their use should be considered as a model that may or may not reflect the enzyme s kinetic properties in biological systems. The thioacylester analogs of phospholipids provide a sensitive spectrophotometric assay for some PLA, or PLAj assays based on the reaction of released thiol with Ellmann s reagent. [Pg.307]

The short life of NO and its low concentration in biological systems make the measurement of this molecule a challenging analytical problem. Among several methods (biochemical assays, UV-Visible spectroscopy, chemiluminescence, EPR) electrochemical methods are considered to be the most suitable for in situ detection of NO in biological milieu. " Generally, the electrochemical oxidation of nitric oxide on solid electrodes proceeds via a two-step (EC mechanism) with an electrochemical reaction as the initial step (heterogenous electron transfer) followed by a chemical reaction. The first electrochemical step is a one-electron transfer from a NO molecule to the electrode residting in the formation of a nitrosonium ion ... [Pg.241]

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See also in sourсe #XX -- [ Pg.116 ]



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