Equipment scintillation counters

The counting equipment used to establish quantitation is radioassay and radioimmunoassays may be either a gamma counter or a liquid scintillation counter depending upon the isotope being used. Most assays use as a label and require a... 

The equipment used in gamma spectroscopy includes a detector, a pulse sorter (multichannel analyzer), and associated amplifiers and data readout devices. The detector is normally a sodium iodide (Nal) scintillation counter. Figure 27 shows a block diagram of a gamma spectrometer. 

Luminescence methods are very sensitive, quantities as little as 1 fem-tomole of ATP being detectable and while measurements may be made using scintillation counters, much simpler equipment that requires neither a radiation source nor a monochromating system is satisfactory. 

Equipment PCR machine, scintillation counter, tabletop centrifuge, temperature-controlled water baths, equipment for horizontal and vertical electrophoresis, UV-illuminator, phosphor imager, automatic DNA sequencer, vacuum dot-blot manifold (Schleicher and Schuell). PCR 0.5 ml hot-start mbes, aerosol resistant pipette rips, autoclaved Eppendorf tubes (all from Fischer Scientific, Brightwaters, NY) and glassware, diethyl pyrocarbonate (DEPC, Sigma)-treated solutions. 

The internal standard ratio method for quench correction is tedious and time-consuming and it destroys the sample, so it is not an ideal method. Scintillation counters are equipped with a standard radiation source inside the instrument but outside the scintillation solution. The radiation source, usually a gamma emitter, is mechanically moved into a position next to the vial containing the sample, and the combined system of standard and sample is counted. Gamma rays from the standard excite solvent molecules in the sample, and the scintillation process occurs as previously described. However, the instrument is adjusted to register only scintillations due to y particle collisions with solvent molecules. This method for quench correction, called the external standard method, is fast and precise. 

Finally, equipment for assaying and analyzing the preparations is needed. Most such equipment is fairly standard in biochemical laboratories and includes spectrophotometers, scintillation counters, analytical gel and capillary electrophoresis apparatuses, immunoblot-ting materials, and immunochemical reagents. 

The desk top computer network is shown in Figure 1. The liquid scintillation counters which we routinely use to generate metabolism data include two Beckman LS-200 series liquid scintillation counters and two Tracor Mark III liquid scintillation counters, however, other LSC makes and models may be interfaced. The Tracor counters are equipped with two standard communications output connectors. One is used to drive the printer, the other is available to the user. The Beckman counters use a unique teletype driver but an interface produced by William Palmer Industries can split the signal and provide a standard communication output. Therefore, all data output from the liquid scintillation counters are available in an electrical standard format, RS-232C. Hardware interfacing was therefore simplified and data collection was a matter of software development. 

Equipment 96-well plate (PET flexible 1405-401 (Wallac, Turku, Finland) (see Note 7) shaker Scintillation counter (Wallac) (see Note 8). 

HPLC system equipped with Partisphere strong anion exchange (SAX) columns (Whatman) and connected to either an on-line (3-radiodetector or a fraction collector. If a fraction collector is used, it will be necessary to quantitate fractions using a 3-scintillation counter. 

X-ray powder diffraction (XRD) profile was measured by an X-ray diffractometer (Rigaku Denki, Ltd., D-9 C, equipped with a scintillation counter), using Cu-Ka radiation with the slit system of RS = 0.15 mm and DS = SS = 1/2° the 20 scan rate was 1/4 or 1/8 "/min. The 20 values were adjusted by the Si (111) reflection, using silicon powder (300 mesh) as the internal standard. Crystal morphology of zeolites was observed by means of scanning electron microscopy (Akashi, Ltd., Alpha-10). 

A Phillips X-ray powder diffractometer equipped with scintillation counter and computer... 

Crystals of the compound of empirical formula FiiPtXe are orthorhombic with unit-cell dimensions a = 8-16, h = 16-81. c = 5-73 K, V = 785-4 A . The unit cell volume is consistent with Z = 4, since with 44 fluorine atoms in the unit cell the volume per fluorine atom has its usual value of 18 A. Successful refinement of the structure is proceeding in space group Pmnb (No. 62). Three-dimensional intensity data were collected with Mo-radiation on a G.E. spectrogoniometer equipped with a scintillation counter. For the subsequent structure analysis 565 observed reflexions were used. The platinum and xenon positions were determined from a three-dimensional Patterson map, and the fluorine atom positions from subsequent electron-density maps. Block diagonal least-squares refinement has led to an f -value of 0-15. Further refinements which take account of imaginary terms in the anomalous dispersion corrections are in progress. 

Intensity results were collected on a General Electric XRD-5 Spectrogoniometer, equipped with a Single Crystal Orienter and scintillation counter, with use of Cu-/fg radiation (nickel filter and pulse-height analyser). Complete three-dimensional measurements were recorded for 6 74° (corresponding to a minimum interplanar spacing d = 0-80 A), and all 193 independent reflections in this range were measurable. The intensities were corrected for... 

The Retina Foundation was a unique place in the late 1950s. The five-story, old tenement house was rebuilt and filled with the most modern biomedical research equipment available. We had analytical ultra-centrifuge, free electrophoresis machine, nuclear magnetic resonance machine, equipment to determine C-14 in the gas phase (before scintillation counters existed), electron microscope, tissue culture equipment with microcinematography, and a superb instrument shop to make new research tools. 

Determination of Radioactivity. All samples were counted in a Nuclear Chicago Isocap 300 liquid scintillation counter equipped with a Teletype computerized for direct calculation of disintegrations per minute. Fifty microliters of blood were directly counted for radioactivity after solubilization (1 mL of 1 N NaOH). After incubation at room temperature for 15 min the sample was decolorized by adding 200 fxL of hydrogen peroxide and incubating at 80°C for 30 min. The processed samples were mixed with 100 fxL of 80% acetic acid and 15 mL of Insta-gel (Packard), and were counted. Approximately 60-100 mg of tissue were solubilized following the same method as for blood. From the collected urine an aliquot (2 mL) was counted directly with 15 mL Insta-gel. The feces were dried overnight at room temperature, and a 60-100-mg aliquot was combusted (12) and counted for radioactivity. 

The experimental set-up consists of a positron source ( Na), a scintillation counter, to detect the y radiation from the positronium decay, and electronic peripheral equipment to analyse the time spectrum of the positron annihilation. 

Instruments/equipment. Tomtec Mach 2 Harvester, Wallac LKB 1205 Betaplate liquid scintillation counter, 96-well polypropylene plates (Costar). 

The XRD profiles of the solid bases were measured on X-ray diffiactometers (Shimadzu VD-II or Rigaku RAD-C) equipped with a scintillation counter under these conditions Cu K a radiation at the intensity of 40kV, 20mA with the slit system of RS=0.6mm, DS=SS=0.5° the 2 0 scanning rate of 2° /min. 

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