Spin dialysis

The radiolabeled DNA may be separated from unincorporated radioactive nucleotides by conventional gel filtration using Biogel P-100 or Sephadex G-100, or by spin dialysis in buffer containing 10 mM Tris-HCl, pH 8.0, and 1 mM EDTA. In either case, the labeled DNA is recovered in the excluded volume. 

Wet spinning of this type of hoUow fiber is a weU-developed technology, especiaUy in the preparation of dialysis membranes for use in artificial kidneys. Systems that spin more than 100 fibers simultaneously on an around-the-clock basis are in operation. Wet-spun fibers are also used widely in ultrafiltration appUcations, in which the feed solution is forced down the bore of the fiber. Nitto, Asahi, Microgon, and Romicon aU produce this type of fiber, generaUy with diameters of 1—3 mm. 

Remove excess reagent and reaction by-products by dialysis or gel filtration using 0.1M sodium phosphate, 0.15M NaCl, lOmM EDTA, pH 7.5. For chromatographic separation, use a desalting gel filtration support such as the Zeba desalting spin columns (Thermo Fisher) or the equivalent. The SAMSA-modified protein may be stored at -20°C until needed. 

Separate excess cystamine and EDC (and reaction by-products) from the modified protein by dialysis or gel filtration using 10 mM sodium phosphate, 0.15M NaCl, pH 7.2. A desalting column may be used for the gel filtration procedure (i.e., Zeba spin columns from Thermo Fisher). 

Purify the modified protein from reaction by-products by dialysis or gel filtration using 50 mM sodium phosphate, 0.15 M NaCl, 10 mM EDTA, pH 7.2. Alternatively, centrifugal spin columns containing a desalting resin may be used for rapid purification (Thermo Fisher). 

Purify the DTPA-dendrimer using dialysis, size exclusion chromatography, or spin-tube concentrators having a molecular weight cutoff of 5,000 Daltons. 

PROTEIN TURNOVER KINETICS WIGNER SPIN-CONSERVATION RULE WOMACK-COLOWICK DIALYSIS METHOD WORK... 

Remove unreacted labeling reagent from the biotinylated antibody by dialysis, gel filtration, or with a spin column. 

Hollow membrane fibers are required for many medical application, e.g. for disposable dialysis. Such fibers are made by usmg an appropriate fiber spinning technique with a special inlet in the center of the spinneret through which the fiber core forming medium (liquid or gas) is injected. The membrane material may be made by melt-spinning, chemical activated spinning or phase separation. The thin wall (15-500 xm thickness) acts as a semi-permeable membrane. Commonly, such fibers are made of cellulose-based membrane materials such as cellulose nitrate, or polyacrylonitrile, polymethylmethacrylate, polyamide and polypropylene (van Stone, 1985). 

Transfer chromatin from dialysis membrane into polypropylene round-bottomed tube. Spin at 12,000g for 10 min in SS-34 rotor. Transfer chromatin into a new tube and divide into 300-pL aliquots (each of which should contain 300-500 pg) in Eppendorf tubes, snap freeze in liquid nitrogen and store at -80°C or use immediately for immunoprecipitation. 

The preparation of B. mori fibroin solution is summarized as follows. The cocoon was degummed twice with 0.5% Marseilles soap solution at 100°C for 0.5 h and then washed with distilled water. The degummed B. mori silk fibroin was dissolved in 9 m MLiBr at 40°C. After dialysis against distilled water for 4 days, the solution was clarified by spinning in a centrifuge at lOOOOrpm for... 

The colloidal state inevitably brings about difficulties for the experimentalist when separation of the disperse phase from the dispersion medium is needed. This is the case when the speciation and concentration of only the free soluble species have to be determined. Separation of the ionic solution from the small colloidal particles for conventional chemical analysis is nontrivial, although separation techniques such as ultracentrifugation, dialysis, and field-flow fractionation have been successfully used. If the soluble species of interest have an active nuclear spin, the liquid NMR technique wiU constitute an alternative and simpler way to characterize and quantify those species without being affected by the disperse phase. An exception is the case where the colloidal species gives a signal that fully overlaps the sharp resonance of the solution entity. As NMR is quantitative, the absolute concentration of the species can be estimated based on an internal reference of known concentration but different chemical shift relative to the sample signals. Alternatively, a calibration curve can be established from a set of external standard solutions (preferably the same substance found in the sample) measured under the same experimental NMR conditions as those applied to the sample. 

Ohbu et. al studied the effect of the degree of quaternary ammonium substitution of cationic cellulose ethers on thekr binding of sodium dodecyl sulfate (SDS) using equilibrium dialysis, dye solubilization, solution density and NMR spin-lattice relaxation measurements. Structures were proposed for different SDS/polymer compositions. The concentration of polymer they studied was such that, at its nominal CMC, SDS was present in stoichiometric excess over the polymer. 

Spin the lysed nuclei at 13,200x for 10 min. Transfer the supernatant to a dialysis tubing (10,000 Da cutoff) without carrying over any solid residue. Dialyze the supernatants against 600 ml extraction buffer for three times (at least 4 h each time) at 4 °C. 

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