DEAE phases

Cationic samples can be adsorbed on the resin by electrostatic interaction. If the polymer is strongly cationic, a fairly high salt concentration is required to prevent ionic interactions. Figure 4.18 demonstrates the effect of increasing sodium nitrate concentration on peak shapes for a cationic polymer, DEAE-dextran. A mobile phase of 0.5 M acetic acid with 0.3 M Na2S04 can also be used. 

The column, designated as TSKgel DEAE-NPR a weak anion exchanger, was 3.5 cm long and 4.6 mm in diameter packed with non-porous resin beads 2.5 ji in diameter. Thus, the maximum efficiency available at the optimum mobile phase velocity would be about 7,000 theoretical plates. The sample was a crude hexokinase product and an... 

Separation on Sephadex DEAE A-25 gel (pH 5.0) and then on CIS silica gel (pH 5.0), absorbances of both systems measured directly in solid phase... 

The pattern of metabolites in bile (animals only) and in urine have been investigated using column chromatography (Amberlite XAD 2 and Sephadex DEAE), tic and reversed phase HPLC in combination with radioactivity monitoring. 

Fig. 5. Effect of the flow rate on the separation efficiency. Separation of a protein mixture at six different flow rates (40,80,120,160,200 and 240 ml/min) normalized to the elution volume. Conditions Column 80 ml CIM DEAE Tube Monolithic Column Mobile phase buffer A 20 mM Tris-HCl buffer, pH 7.4 buffer B 20 mM Tris-HCl buffer + 1 M NaCl, pH 7.4 Gradient 0-100% buffer B in 200 ml Sample 2 mg/ml of myoglobin (peak 1), 6 mg/ml of conalbumin (peak 2) and 8 mg/ml of soybean trypsin inhibitor (peak 3) dissolved in buffer A Injection volume 1 ml Detection UV at 280 nm. (Reprinted with permission from Podgornik A, Barut M, Strancar A, Josic D, Koloini T (2000) Anal Chem 72 5693)...

Fig. 7. Semi-Preparative Anion Exchange Purification of a 16-mer Oligodeoxynucleotide on a CIM DEAE Disk Monolithic Column. Conditions Column 0.34 ml CIM DEAE Disk (3X12 mm ID) Instrumentation Gradient HPLC system with extra low dead volume mixing chamber Sample 16mer oligodeoxynucleotide from the reaction mixture - bold line, standards of 1,2,3,4,5,6,7,9,10,11,12,14,15,16mer- thin line Injection Volume 20 pL Mobile Phase Buffer A 20 mM Tris-HCl, pH 8.5 Buffer B Buffer A+ 1 M NaCl Gradient as shown in the Figure Flow Rate 4 ml/min Detection UV at 260 nm...

In preliminary experiments we have further purified the DEAE eluate by extracting it with ether. The DEAE extract (dissolved in 0.45% NaCl) was shaken vigorously for 3 min. (4 C) with an equal volume of diethyl ether, the layers were separated and ether evaporated under a stream of N2 from both the aqueous and ether phases, designated DEAE ether extract and ether layer respectively. An ether control was run at the same time using just 0.45% NaCl in place of the DEAE extract. As shown in Table III, extracting with ether had no effect on the airway constrictor activity of the DEAE extract. The percent activity after (97%)... 

Geranylgeranyl pyrophosphate [6699-20-3] M 450.5. Purified by counter-current distribution between two phases of a butanol/isopropyl ether/ammonia /water mixture (15 5 1 19) (v/v), or by chromatography on DEAE-cellulose (linear gradient of 0.02M KCl in ImM Tris buffer, pH 8.9). Stored as a powder at 0°. 

Chemically modified cellulose supports are also used in TLC, either as fibres or a crystalline powder. The most widely known of these is DEAE-cellulose, a basic phase containing diethylaminoethyl groups. The hydrophilic character of other polar phases with ion exchange properties can be used for the separation of ampholytes. 

Center and Behai (49) have resolved 5 -nucleotidase from calf intestinal mucosa into three fractions using DEAE-cellulose chromatography. One of these was obtained free of nonspecific phosphatase. It had a pH optimum of 6-6.5, Mn2+, Mg2+, and Co2+ (1-10 mill) all enhanced activity and complete inactivation was produced with 1 mM EDTA. This enzyme hydrolyzes all 5 -ribonucleotides at similar rates and hydrolyzes 5 -deoxribonucleotides more slowly. These properties indicate that it is strikingly similar to the one obtained from acetone powder preparations of chicken and rat liver (32, 33) and from soluble supernatants of rat liver (36). The other two activities (which were not fully characterized) (49) could possibly have originated from particulate material or membranes because the authors employed deoxycholate in the early phase of purification. 

The neutral lipid fraction from the DEAE-Sephadex A-50 column was combined with the lower phase obtained after Folch partition of the total lipid extract and the combined lipids dried. To the same flask, 10Q ml of 0.6 M NaOH in methanol was added. The mixture was incubated at 37°C for 5 hours. Five volumes of acetone were then added and stored overnight at 4°C. The precipitate was collected by centrifugation at 4°C and dissolved in C M (4 1, v/v). After application to the column (2.0 x 25 cm), the column was washed with chloroform. Neutral glycolipids were then eluted with tetrahydrofuran H2O (10 1). Fractions containing neutral glycosphingolipids were pooled and their glycolipid content examined by thin-layer chromatography. 

Application of buffered tetrahydrofuran extraction to gastric mucosa, followed by careful examination of the aqueous phase for various glycosphingolipids, indicated that this phase contained sialoglycosphingolipids and considerable quantities of neutral glycosphingolipids (22). These were separated from the acidic glycosphingolipids by DEAE-Sephadex column chromatography (23). 

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