Dialyser

Artificial kidney dialyser Artificial turf Artimte [12143-96-3] Artists colors Arvin [9046-56-4]... 

Fig. 43. Schematic of a hoUow-fiber artificial kidney dialyser used to remove urea and other toxic metaboUtes from blood. Several million of these devices...

Sodium hydrogen zirconium phosphate [34370-53-17 is an ion-exchange material used in portable kidney dialysis systems which regenerate and reckculate the dialysate solution. The solution picks up urea during the dialysis. The urea reacts with urease to form ammonia, which is absorbed by the sodium hydrogen zirconium phosphate. 

Fig. 2. Schematic of alcohol reduction ia beverages. Countercurrent dialysis is combiaed with distillation. The separation process is isothermal, and high boiling iagredients, present ia the dialysate, are preserved. In this fashion, alcohol removal is accompHshed with minimal perturbation ia flavor.

Until the early 1960s, laboratory iavestigators rehed on dialysis for the separation, concentration, and purification of a wide variety of biologic fluids. Examples iaclude removal of a buffer from a proteia solution or concentrating a polypeptide with hyperosmotic dialysate. Speciali2ed fixtures were sometimes employed alternatively, dialysis tubes, ie, cylinders of membrane about the si2e of a test tube and sealed at both ends, were simply suspended ia a dialysate bath. In recent years, dialysis as a laboratory operation has been replaced largely by ultrafiltration and diafiltration. 

Fig. 4. Schematic of a hemodialyzer. The design of a dialyzer is close to that of a sheU and tube heat exchanger. Blood enters through an inlet manifold, is distributed to a parallel bundle of fibers, and exits into a coUection manifold. Dialysate flows countercurrent in an external chamber the blood and dialysate are separated from the fibers by a polyurethane potting material. Housings are typically prepared from acrylate or polycarbonate. Production volume is...

For consistency, clearance here is expressed in cm /s although the more common clinical units, and those used later in this chapter, are ml,/min. Combination and rearrangement of equations 6—8 allows clearance to be estimated from mass-transfer coefficient and vice versa the conditions of countercurrent flow with no dialysate recycling are shown below. 

Fig. 6. Solute transport in hemodialysis. Clearance vs solute mol wt for dialy2ers prepared from the two different membranes illustrated in Figure 5. Numbers next to points represent in min /cm calculated from equations 10 and 5. Data is in vitro at 37°C with saline as the perfusion fluid. Lumen flow, dialysate flow, and transmembrane pressure were 200 ml,/min, 500 mL/min, and 13.3 kPa (100 mm Hg) area = 1.6. Inulin clearance of the SPAN...

Barium sulfate [7722-43-7] M 233.4, m >1580 . Washed five times by decantation with hot distilled water, dialysed against distd water for one week, then freeze-dried and oven dried at 105° for 12h. 

Sodium carboxymethylcellulose [9004-32-4]. Dialysed for 48h against distilled water. 

Deoxyribonucleic acid (from plasmids). Purified by two buoyant density ultracentrifugations using ethidium bromide-CsCl. The ethidium bromide was extracted with Et20 and the DNA was dialysed against buffered EDTA and lyophilised. [Marmur and Doty J Mol Biol 5 109 1962 Guerry et al. J Bacteriol II6 1064 1973.] See p. 504. 

Dibydropteridine reductase (from sbeep liver) [9074-11-7] Mr 52,000 [EC 1.6.99.7]. Purified by fractionation with ammonium sulfate, dialysed versus tris buffer, adsorbed and eluted from hydroxylapatite gel. Then run through a DEAE-cellulose column and also subjected to Sephadex G-lOO filtration. [Craine et al. J Biol Chem 247 6082 1972.]... 

For plasminogen-deficient fibrinogen from blood plasma, the anticoagulated blood was centrifuged and the plasma was frozen and washed with saline solution. Treated with charcoal and freeze-thawed. Dialysed versus Tris/NaCl buffer. [Maxwell and Nikel Biochem Prep 12 16 1968.]... 

FIGURE 5A.2 A dialysis experiment. The solution of macromolecules to be dialyzed is placed in a semipermeable membrane bag, and the bag is immersed in a bathing solution. A magnetic stirrer gently mixes the solution to facilitate equilibrium of diffusible solutes between the dialysate and the solution contained in the bag. 

If a solution of protein is separated from a bathing solution by a semipermeable membrane, small molecules and ions can pass through the semipermeable membrane to equilibrate between the protein solution and the bathing solution, called the dialysis bath or dialysate (Figure 5A.2). This method is useful for removing small molecules from macromolecular solutions or for altering the composition of the protein-containing solution. 

Dialyse, /. dialysis, dialirsierbar, a. dialyzable. dialirsieren, v.t. dialyze. 

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