Detergent sodium dodecyl sulfate SDS

An electrophoretic method commonly employed for estimation of purity and molecular weight makes use of the detergent sodium dodecyl sulfate (SDS). 

Morphological analysis showed different sizes for polyhedra produced from cell culture and caterpillar (Bonning et al., 1995). On other hand, the polyhedra number is inversely proportional to cell size (Federici, 1986). In addition, the polyhedra produced in vitro is more sensitive to detergent (sodium dodecyl sulfate, SDS) treatment than polyhedra produced in vivo (Lua et al., 2003). All these differences may be related to biochemical differences observed between the infected cells in vitro and in vivo (Bonning et al., 1995). Another characteristic of polyhedra produced in vitro is the so-called passage effect , which is discussed below. 

In the presence of the detergent sodium dodecyl sulfate (SDS), many proteins are disaggregated and unfolded. As with elution volume, the electrophoretic mobility of SDS-denatured polypeptide chains is a monotonically decreasing function of molecular weight, and the molecular weight of an unknown protein may be inferred from the mobilities of standards. 

The isolation of bacterial DNA described in this experiment, patterned after the work of Marmur (1961), accomplishes these objectives. Bacterial cells are disrupted by initial treatment with the enzyme, egg-white lysozyme, which hydrolyzes the peptidoglycan that makes up the structural skeleton of the bacterial cell wall. The resultant cell walls are unable to withstand osmotic shock. Thus, the bacteria lyse in the hypotonic environment. The detergent, sodium dodecyl sulfate, (SDS, sodium do-decyl sulfate) then completes lysis by disrupting residual bacterial membranes. SDS also reduces harmful enzymatic activities (nucleases) by its ability to denature proteins. The chelating agents, citrate and EDTA (ethylenediamine tetraacetic acid), also inhibit nucleases by removing divalent cations required for nuclease activity. 

Electrophoretic techniques also yield estimates of the molecular weights of proteins and nucleic acids. The detergent sodium dodecyl sulfate (SDS) and proteins form... 

Deinococcu radiodurans, with 2-3 nm pores and widths of 5-6 mn (Fig. 13.11). The surface layer proteins were bound to the cells by hydrophobic interactions and were extracted using a detergent, sodium dodecyl sulfate (SDS). The resulting templates have been randomly dispersed on conductive substrates for through-mask deposition of Cu O, Ni, Pt, Pd, and Co [82]. 

Two dimensional electrophoresis provide ultrahlgh resolution of various proteins (29). For example, by combining isoelectric focusing (lEF) with perpendicular electrophoresis in the presence of the detergent sodium dodecyl sulfate (SDS), the resulting resolution of 10,000 proteins could be theoretically obtained. Samples of human cells showed 100-2000 protein spots. 

The detergent sodium dodecyl sulfate (SDS) often efficiently extracts unreduced storage proteins. For SE-HPLC, proteins may be extracted with an SDS-containing buffer similar to the mobile phase. Usually the SDS concentration is increased to 1-2% and the sample is heated to ensure total complexing with protein [8,39]. To extract all proteins without reduction, SDS plus mechanical (ultrasonic) shear may also be used [40,41] but may decrease the size of native glutenin. 

SDS-Polyacrylamide Gel Electrophoresis Polyacrylamide gel electrophoresis is often used simultaneously for both separating and estimating the molecular weight of proteins that are solubilized with the detergent sodium dodecyl sulfate (SDS). This special kind of electrophoresis is called SDS-polyacrylamide gel electrophoresis or SDS-PAGE. 

Bunton provided the first report on the effect of micelles formed by the cationic detergent cetyltrimethylammonium chloride (CTAC) and those formed by the anionic detergent sodium dodecyl sulfate (SDS) on the nucleophilic attack of the phosphate triester p-nitrophenyl diphenylphosphate by fluoride and hydroxide ions. In agreement with work on other reactions... 

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