Sedimentation equilibrium in a density gradient has recently been developed into a reliable method for the determination of molecular weights of homogeneous DNA samples. The procedure and calibrations required for this method are outlined in this paper. In 1957, Meselson, Stahl and Vinograd' introduced a remarkable analytical technique for studying the properties of DNA and viruses. Sedimentati...

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The generalized gradient approximation (GGA) corrects many of the shortcomings of the local spin-density (LSD) approximation. The accuracy of GGA for ground-state properties of molecules is comparable to or better than the accuracy of conventional quantum chemical methods such as second-order Møller-Plesset perturbation theory. By studying various decompositions of the exchange-correlation ener...

Matthew Meselson, Franklin Stahl, and Jerome Vinograd, developed cesium chloride, or CsCl, density gradient centrifugation in the 1950s at the California Institute of Technology [5], or Caltech, in Pasadena, California. Density gradient centrifugation enables scientists to separate substances based on size, shape, and density. Meselson and Stahl invented a specific type of density gradient cent...

Studies on normal human reticulocytes have been limited by a lack of methods for effective reticulocyte enrichment. This study shows a convenient new approach for selective enrichment of reticulocytes from normal blood samples. We have developed a modified arabinogalactan density gradient that contains high potassium levels, approximating the internal cation composition of red blood cells (RBC)...

Recently we described (Electrophoresis 5: 143-147, 1984) a new device for producing density and solute gradients, involving computer-controlled coöperation of stepmotor-driven high-precision burettes, the purpose being to substantially improve reproducibility, flexibility, and documentation of gradients used in gels and in other applications in biochemistry. Here we present the functional princ...

A crude pea (Pisum sativum L. var. Homesteader) mitochrondrial preparation was divided into two equal parts. One part was layered on a Dextran-40 step gradient, and the other on a sucrose step gradient, and they were centrifuged to obtain different bands of particles. The densities at which the particles banded and the mitochondrial respiratory activities of the particles were determined. Dextr...

OBJECTIVES Implantation of cell separation and mesenchymal stem cell culture techniques from human umbilical cord blood with and without using the Ficoll-Paque gradient density method (d=1.077 g/ml). METHODS Ten samples of the umbilical cord blood obtained from full-term deliveries were submitted to two different procedures of mesenchymal stem cell culture: a) Method without the Ficoll-Paque ...

The Mg(BiO2)2 is the orthorhombic crystal system acting as semiconductor in electric devices. To evaluate electronic band structures, the total density of state (TDOS) and the partial density of state (PDOS), Generalized Gradient Approximation (GGA) based on the Perdew–Burke–Ernzerhof (PBE0) was used for Mg(BiO2)2. The band gap was recorded at 0.959 eV, which is supported by a good semiconducto...