Autoradiography materials

The distribution of impurities over a flat sihcon surface can be measured by autoradiography or by scanning the surface using any of the methods appropriate for trace impurity detection (see Trace and residue analysis). Depth measurements can be made by combining any of the above measurements with the repeated removal of thin layers of sihcon, either by wet etching, plasma etching, or sputtering. Care must be taken, however, to ensure that the material removal method does not contaminate the sihcon surface. 

TLC Analysis. Samples were examined by TLC using standard procedures. Rf values were determined and compared with those of authentic reference materials. Radioactive components were located by scanning (Vanguard Instrument Corp., North Haven, Conn., Model 885) or by autoradiography (Eastman Kodak, Rochester, N. Y., type AA film). The relative Rf value of DCDD on silica gel plates (Brinkmann Instruments, Inc., Westbury, N. Y., type For,4) when developed with n-hexane dioxane acetic acid, 90 10 4, V/V/V, was 0.90. The observed impurity had a relative Rf value of 0.40. On Brinkmann alumina plates, developed with n-hexane, DCDD had a relative Rf of 0.32. Neither system separated the chlorinated dibenzodioxin isomers. 

Examples of PLC with autoradiography detection include the published studies on labeling of l- H-PAF-aceter [25] diazinon and related compounds from plant material [26] metabolic fate of triamcinolone acetonide in laboratory animals [27] synthesis of 4-S-cysteaminyl-[U- " C]phenol antimelanoma agent [28] radiolabeled... 

Reports are published on the metabolism of methoprene by plants (25), aquatic microorganisms (26), soil microbes (27), house flies and mosquitoes in vivo (28), resistant house flies in vivo and in vitro (29), a steer (30), a lactating cow (31), chickens (32), and bluegill fish (33). In addition, radioactive material balance studies have been published for a guinea pig, steer, and cow (34), chickens (35), and rats (36, 37), including whole-body autoradiography in rats (37). 

The firagments in the material to be analyzed (DNA, RNA, or protein) are separated by gel electrophoresis. The smaller molecules travel faster and appear nearer the bottom of the gd. The bands of material in the gel are transferred or blotted to the surface of a membrane. The membrane is incubated with a (usually radioactive) labeled probe that will specifically bind to the molecules of interest. Visualization of the labded probe (usually by autoradiography) will reveal which band interacted with the probe. The most common types of blots are compared in Table 1-7-1. Most typically, DNA restriction fragments are analyzed on a Southern blot. 

Additional materials Cling-film (see Note 7), an autoradiography cassette and autoradiography film (see Note 8). Access to a darkroom is also required along with film-processing facilities (see Note 9)... 

Subsequent to recovery of the total lipids of a cellular preparation as a chloroform-soluble fraction, the total phosphorus content can be determined (see Chapter 3) and then, depending on the amount of lipid phosphorus (or whether the preparation is radiolabeled or not, see below), analytical and/or preparative thin-layer chromatography can be undertaken. In either case, if the experimental protocol is centered on a signal-transduction process, then there may be insufficient material for a phosphorus analysis. In the latter instance, the cellular preparation is prelabeled with 32P or [3H]inositol and the labeled products are located by autoradiography. A preferred type of adsorbent (for thin-layer chromatography) is Merck silica gel 60 (oxalate impregnated). An effective solvent for separation of the phosphatidylinosi-tols and other lipids is chloroform-acetone-methanol-acetic acid-water (80 30 26 24 14, v/v). The approximate / values of cellular phospholipids under these conditions are presented as follows ... 

The brain distribution and binding of Ro 15-4513 has been evaluated recently by autoradiography and positron emission tomography (PET) techniques using [ C]-Iabelled material. Autoradiographic analysis of... 

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