Precipitation during dialysis

Dialyze the antibody fractions (detected by ELISA) against PBS or HBS to remove imidazole and NaCl (typical yields are 0.2-20 mg/L of culture). Some antibodies tend to precipitate during dialysis The precipitation is associated with the presence of the his-tag. Addition of 20 mM EDTA to the antibody sample before dialysis often solves this problem. 

In the experiments of Hayes et al. (1975) DMSO was marginally better than DMF or sulfolane for dissolving humic substances (Table 4). In the ESR there was evidence of a higher free radical concentration in DMSO than in either DMF or sulfolane. Because DMSO would not be expected to generate free radicals, it is reasonable to infer from the ESR data that humic components, which are insoluble in the DMF- and sulfolane-water systems, were dissolved in this solvent. Elemental contents were similar for the humic and fulvic acids of the DMSO extracts, and these data infer that the major difference between the two fractions was one of molecular size. However, some fulvic acid materials were observed to precipitate during dialysis, as was noted for the DMF and sulfolane systems. 

Effect of dialysis Stem juice dialysed against distilled water for 16 hours. PG inhibitor activity was examined in the dialysate after 16 hours after removal of precipitate by centrifugation. Table 4 shows that the inhibitor is more or less non-dialysable although a part of its activity is lost during dialysis. Dialysis results in about 3 fold purification of the inhibitor. Dialysed inhibitor was used in subsquent studies. 

Centrifuge dialysate (8000g, 10 min, 4°C) to remove any precipitate formed during dialysis. 

Complete precipitation by PEG needs 30 min to 15 h at 0 ° C. The precipitate is collected by centrifugation or filtration on glass fiber filters (e.g., Whatman GF/A). Dissolve the precipitate in ddHaO and dialyze against an appropriate buffer. An increase in volume occurs during dialysis. 

We have recently found that for recombinant RANTES purifications the gel filtration step in guanidine/HCl can be replaced by dialysis against 1% acetic acid. The RANTES protein remains soluble while the contaminating proteins precipitate during the dialysis. The RANTES is recovered in the supernatant after cen-... 

As noted by Ito e al. (53), methionase was activated by heating at 60°C for 10 min. The greatest increase in activity for the methlonlnase was observed for a 50% saturated ammonium sulfate precipitate (4.6-fold), but this was substantially less than the 20-fold increase obtained by Tanaka et al. (52, 59) when a DEAE-cellulose column fractionation step was also employed before salt precipitations. A DEAE-cellulose step was not included in the current study because emphasis was directed towards provision of a more stable medium than maximum activity. Loss of activity noted during dialysis steps was later found to be retarded by incorporation of 2-mercaptoethanol into the dialysis buffer. However, loss of activity of the 1 . putlda methlonlnase when in solution occurred readily, and the data in Figure 2 illustrate this behavior. Freeze-dried methlonlnase powder lost little activity when assayed after holding at -20°C for periods up to one year, and when rehydrated was more stable than the initial cell... 

The PAW extract is diluted with distilled water and dialyzed (Visking, size 7) first against 25% (v/v) acetic acid and then against several changes of distilled water. During dialysis, a flocculent brownish-white precipitate separates in the tubing this precipitate contains mainly deoxycholic acid... 

Ti-Aspartic Oxidase. Aspartase and transaminases account for a major part of the metabolism of L-aspartic acid. n-Aspartic acid is oxidized by an enzyme present in liver and kidney. This is an oxidase that converts aspartate to oxalacetate and ammonia while reducing oxygen to hydrogen peroxide. The oxidase was resolved by ammonium sulfate precipitation and dialysis to a protein that could be reactivated by FAD but not by FMN. The enzyme differs from n-amino acid oxidase in its insensitivity to benzoate. The only other known substrate for the partially purified D-aspartic oxidase is D-glutamate, but since the relative rates of oxidation of the two amino acids vary during the preparation of the enzyme, it is... 

Solid ammonium sulfate is added to the solution to 35% saturation. After filtration, ammonium sulfate is added to the filtrate to 95% saturation. The respiratory components are precipitated. The precipitate is collected with the aid of Hyflo Super-Cel and is dissolved in distilled water and centrifuged to remove the Hyflo Super-Cel. The resulting supernatant is dialyzed against running water for 1 day at below 10°C. The insoluble matter formed during dialysis is removed by centrifugation. 

Preheat 2 L of distilled water to 75 °C in an oven, then add 20 g unhydrolyzed crystals of Fe(N03)3 9H2O with rapid stirring. Return to the oven and leave there for 10-12 min. During this time the solution changes from gold to dark reddish brown indicating the formation of Fe hydroxy-polymers. No precipitate should form. Cool rapidly by plunging into ice water, transfer to a dialysis bag and dialyse for at least... 

The initial rate of polymerization versus base molar concentration ratio of template to monomer shows a sharp maximum in the range of [T]/[M] = 1.5. Polymerization was initiated by AIBN and UV light at 365 nm. Poly(dimethylaminoethyl methacrylate) with polyCacrylic acid) give a complex. During polymerization, precipitation takes place. From the product obtained, the daughter polymer and the template were isolated by dissolving the complex in 10% NaCl solution, addition of proper amount of NaOH, followed by dialysis. 

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