Acetone precipitation

Repeet Acetone Precipitation and Centrifuge to Recover Neomycin... 

In order to choose among these various hypothesis, we followed the kinetic of secretion of the polygalacturonase in the Pg glc medium. Hence, the proteins present in daily aliquots have been acetone precipitated The protein extracts were then either placed on a reaction medium to assay for their PG activity or studied by zymogram [5],... 

A crude protein extract has been prepared by acetone precipitation on a three days old culture supernatant of the SCPP strain on Pg glc medium. In order to estimate the effect of glucose on PG activity, these protein extracts were deposited as dots on solid Pg glc medium. 

Both the acetone-precipitated polymer (I) and the polymer recovered by removal of the solvent from the acetone-xylene filtrate (II) had a higher [tj ] when MAH was present in the charge, although the amount of acetone-precipitated polymer (I) was decreased when MAH had... 

Acetone precipitated CDE and CBE caused minimal contraction of the rat stomach smooth muscle. The supernatant retained most of the active substance (64). Butanol, however, did extract the active components of both CBE and CDE ( ). Ethyl acetate, which will extract 5HT from an aqueous solution ( ), was unsuccessful in removing the active components. These findings are in agreement with Russell t l. (66), who used this procedure to demonstrate that the active component of bract was "5HT-like." The active agent(s) in extracts of the dust and bract were demonstrated to have a molecular weight below 20,000. 

Table IV. Bioassay of Crude Ether Soluble Acetone Filtrate (ESAF), Ether Soluble Acetone Precipitate (ESAP), Water Soluble Acetone Filtrate, (WSAF), and Water Soluble Acetone Precipitate (WSAP) From Prorocentrum concavum Using 10 Female Mice for Each (ip) Injected Dose.

Figure 4. Dose response curves representing per cent mortality (within 48 hours) of approximately 20 g mice (CRE CD BR ICR) injected with specified doses of ether soluble acetone filtrate (ESAF), ether soluble acetone precipitate (ESAP), water soluble acetone filtrate (WSAF), and water soluble acetone precipatate (WSAP) from Prorocentrum concavum (SIU 364). Each dose was administered by ip injection into 10 mice. LD50S were determined using probit analysis. A correlation coefficient (R) is provided for each LD5Q.

At temperature lower then 50°C, polymerization proceeds very slowly, whereas at 50°C, 4-vinylpyridine and 2-vinylpyridine polymerize very rapidly without any initiator. Using DMF as solvent, the system remains homogeneous through the polymerization time, whereas in acetone precipitates polymer mixture after a few minutes. It is also... 

The purification of tetryl aims at removing by-products such as tetranitro derivative (VII), substances insoluble in benzene and the spent acid occluded by the crystals. The product is washed with cold water and then treated with hot water. This brings about the conversion of compound (VII) to (VIII)—the latter is soluble in hot water. The tetryl is then dissolved in benzene and insoluble constituents removed by filtration. The resulting solution is washed with water until it is completely free from acid. Alternatively, tetryl may be dissolved in acetone, precipitated with water, and finally deacidified. 

When our work started, the phase transitions was observed only for weakly charged networks of PAA gels swollen in the mixtures of water (good solvent) with acetone (precipitant) of different compositions. The first stage of our work was the investigation of the nature and polarity of a precipitant on the position and the amplitude of the phase transition. According to the results of theoretical consideration of Refs. [7,18,20], the transition point and the value of the jump of the volume are primarily determined by the network structure and by the parameter of polymer-solvent interaction Xns- By smoothly changing the composition of the binary solvent, it is possible to vary effective value of the Xns parameter and to convert the network to a collapsed state. In this case, the amplitude of phase transition should not depend on the nature of precipitant. 

The polyphenol oxidase was obtained from extracts of the pressed grape juice sediment by acetone precipitation, purified on Sephadex G 25 and DEAE-Sephadex A 25, and further concentrated by ultrafiltration. Model experiments were done in a Warburg apparatus (10). The grape skin waxes were extracted with pentane. The resulting extracts were analyzed by a GLC (Varian Aerograph, model 1201) which was coupled via a helium separator according to Watson and Bieman (19) to a mass-... 

Pectin content of Eastern grape musts, determined by acetone precipitation (37), was observed over a five-year period, Table V. Daily... 

During fermentation, 30-90% of the pectins are precipitated (5). An analysis of pectin content of wines from native and hybrid varieties (Table IX) for the years 1970 and 1971 indicate a reduction of 75-95% during fermentation. It is probable that the acetone-precipitable material remaining in the wine is gum or partially hydrolyzed pectin since the precipitate, a grey amorphous material, is entirely different from the translucent gelatinous mass typical of precipitated pectin. Although pectin is a problem in hot pressing native and hybrid varieties, the pectin content of the wine is comparable with that of vinifera wine. 

Acetone precipitates. The aqueous immunogen is precipitated with 4.5 vol acetone at-20°C. The precipitate is collected by centrifugation at l0,000g at room temperature, washed in 80% acetone, and air-dried The pellet is resuspended in saline using a Dounce homogemzer, and then administered directly or in association with alum or Freund s adjuvants. 

These particulate, and also many apparently soluble, DPO enzyme preparations frequently exhibit the phenomenon of latency. This is manifested as atypically low DPO activity when the tissue is known to be rich in DPOs. When the enzyme is treated with a chaotropic agent such as SDS or 8 M urea, or is subjected to an acetone-precipitation procedure, a marked increase in DPO activity is revealed (Palmer, 1963 Walker and Hulme, 1965). This effect is thought to come about by the release of the membrane-bound enzyme and/or effects upon the tertiary structure of the enzyme and the active site. 

Selective adsorption on glass Ammonium sulfate fractionation Ammonium sulfate fractionation Ethanol precipitation Sonic disintegration Selective adsorption on cellulose phosphate CM-cellulose chromatography Acetone precipitation Ammonium sulfate fractionation Ethanol precipitation Selective adsorption on cellulose phosphate Ammonium sulfate fractionation Lysozyme and trypsin digestion Ammonium sulfate fractionation DEAE-cellulose chromatography Ammonium sulfate fractionation... 

Since the acetone precipitation step is not applicable to all venoms, the decision of which method to use depends on the availability of the starting venom Crotalus adamanteus (35), Bothrops atrox (44), Heina-chatus haemachates (43), and Vipera lebetina (48). 

An acetone powder of Savoy cabbage leaves (prepared by heat coagulation and acetone precipitation and available from commercial sources) is suspended in diethyl ether and then filtered. The residue is dispersed in sodium acetate and calcium chloride at pH 5.0, and the insoluble matter is separated by centrifugation at 13,000 g for 10 min at 4°C. The supernatant contains all the phospholipase D activity and in our laboratory s experience can be used successfully in any experiment requiring this enzymatic activity. It can be maintained at -20°C for 1-2 weeks. 

The lower, chloroform-rich phase is separated carefully from the protein-containing interface, and then it is washed twice with methanol-water (10 9, v/v) and the washes are discarded. The chloroform layer contains the phosphatidic acid (as a sodium salt) and can be isolated by acetone precipitation. The yields can be of the order of 90-95%. One alternative route to identification of the chloroform-soluble material is to analyze it for total phosphorus and total fatty acid ester (see procedures described earlier). In the case of diacylphosphatidylcholine as the substrate, the fatty acid ester/P molar ratio should be 2.0. Another approach is to subject the chloroform-soluble fraction to preparative thin-layer chromatography on silica gel H (calcium ion free) in a two-dimensional system with a solvent system of chloroform-methanol-28% ammonium hydroxide (65 35 6, v/v) in the first direction and a solvent system of chloroform-acetone-methanol-glacial acetic acid-water (4.5 2 1 1.3 0.5, v/v) in the second direction. The phosphatidic acid will not migrate far in the basic solvent Rf 0.10) and will show an Rf value one-half of that of any remaining starting substrate (fyO.40) in the second solvent. Of course with a simple substrate system, one can use the basic solvent in one dimension only... 

Diorgano tellurium dihalides, when refluxed with silver fluoride in toluene, tetrahydro-furan, or acetone, precipitate silver halides. The diorgano tellurium difluorides crystallize upon cooling the filtrate of the reaction mixture or evaporating the filtrate under vacuum. 

Albumin can be measured quantitatively by the bromcresol green method in most species (Evans and Duncan 2003). Other proteins (described below) are measured by immunometric methods. Newer methods based on proteomics technology (concentration of proteins by acetone precipitation or ultracentrifugation, separation by 2-d gel electrophoresis or chromatographic techniques with subsequent identification and quantitation by mass spectrometry) have been used experimentally (Bandara and Kennedy 2002 Chapman 2002 Thongboonkerd et al. 2002a, b). 

Thongboonkerd V, McLeish KR, Arthur JM, Klein JB (2002) Proteomic analysis of normal human urinary proteins isolated by acetone precipitation or ultracentrifugation. Kidney Int 62 1461-1469... 

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