Precipitation with ethanol

The caseins may be precipitated from milk by c. 40% ethanol while the whey proteins remain soluble lower concentrations of ethanol may be used at lower pH values. 

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A pepsin hydrolysate of flounder fish protein isolate has been used as the substrate (40% w/v) for plastein synthesis, using either pepsin at pH 5 or alpha chymotrypsin at pH 7, with an enzyme—substrate ratio of 1 100 w/v at 37°C for 24 h (151). The plastein yields for pepsin and alpha chymotrypsin after precipitation with ethanol were 46 and 40.5%, respectively. 

Pish silage prepared by autolysis of rainbow trout viscera waste was investigated as a substrate for the plastein reaction using pepsin (pH 5.0), papain (pH 6—7), and chymotrypsin (pH 8.0) at 37°C for 24 h (152). Precipitation with ethanol was the preferred recovery method. Concentration of the protein hydrolysate by open-pan evaporation at 60°C gave equivalent yields and color of the final plastein to those of the freeze-dried hydrolysate. 

Iron(II) fluoride tetrahydrate [13940-89-17, Fep2 4H2O, is prepared by dissolving iron metal ia warm hydrofluoric acid and precipitating with ethanol. The stmcture of the soHd consists of discrete [FeF2(H20)4] octahedra ia which F and H2O are randomly distributed over the possible sites. The white sohd turns brown ia air and decomposes at 100°C. It is slightly soluble ia water, alcohol, and ether and is soluble ia dilute acid. 

Some hemicelluloses are partiaUy extractable with water, but they are usuaUy extracted with alkaline solutions foUowing removal of Upids and lignin. DeUgnifted plant material is termed, holoceUulose. Neutralization of the alkaline extract effects precipitation of the more linear and less acidic hemicelluloses, termed the hemiceUulose A [63100-39-0] fraction. The more acidic and more branched material, termed hemiceUulose B [63100-40-3], is precipitated with ethanol (70%). HemiceUulose B types type are usuaUy water-soluble after extraction. 

By extraction of poppy-heads or opium with water, precipitation with aqueous Na2C03-solution, washing of the precipitate with ethanol and dissolving in diluted acetic acid. 

C2F4 reacts with both [HCo(CN)j] and [Co(CN)j] to give, respectively, [HCF2CF2Co(CN)j] -and [(CN)5CoCF2CF2Co(CN)j]"-. The reaction takes place in aqueous solutions at atmospheric pressure 122,121). The presence of potassium amalgam in the former case produces [HCo(CN)5] which gives almost exclusively the HCF2CF2 product. The complexes were isolated by precipitation with ethanol 121). The reaction of [Co"(CN)5] - with CS2 produces [(NC),CoS—C—Co(CN)5] - 125, 5). 

Isolation and characteristics of the polysaccharides. It is known (1,3,4,6) that the polysaccharides from a culture medium can be precipitated by adding different volumes of ethanol (1 2, 1 3). Our experiments with precipitation with ethanol at a ratio of 1 3 led to the isolation of crude polysaccharides from the culture medium (Sample 1). 

A second polysaccharide fraction (Sample 3) was isolated from the filtrates by concentration and following precipitation with ethanol (1 3). The yield and characteristics of the obtained polysaccharides (Samples 2 and 3) are given in Table 1. It is evident that the sum of the yields for Samples 2 and 3 is almost equal to the yield for Sample 1. The polyuronic content data are also well balanced. This fact indicates that the suggested method is suited for fractional isolation of the polysaccharides from the spent culture medium of H.annuus 1805 cell suspension. As can be seen from Table 1, the main part of the exopolysaccharide was in fraction I. 

The highest degree of purification was achieved with extracellular endopectate lyase from the anaerobic bacterium Clostridium fel-sineum.Mi A 225-fold purified preparation, homogeneous in disc electrophoresis, was obtained by precipitation with ethanol, and chromatography on CM-cellulose and on Sephadex G-200. Its molecular weight (determined by gel chromatography) was 105,000. 

Illustrated for 5-methoxy-tryptamine (1). 1.5 g (1), 30 ml ethanol add 5 g methyl iodide (or equimoiar amount ethyl iodide) and 4.5 g dry sodium carbonate and heat five hours on water bath. Filter hot, heat precipitate with ethanol and filter hot again. Evaporate in vacuum to get 2.5 g l-methyl-5-methoxy-DMT. 

As stated above, the PM of tomatoes is inactivated easily and completely by precipitation with ethanol. This method can be used for a quantitative separation of the PM and PG of tomatoes. 

The (3-lorm is obtained by dissolving crude quinacridone in any one of a variety of solvents (such as concentrated sulfuric acid/toluene or methylated sulfuric acid), followed by precipitation with water. The same end is achieved by dissolving the product in polyphosphoric acid, followed by rapid precipitation with ethanol at 45°C. The (3-product, however, is not pure and usually contains some a-crystal modification as well. 

The DNA band is cut from the gel and placed in a dialysis bag containing a small volume of buffer. The bag is placed in an electrophoretic tank and, when the current is switched on, the DNA passes out of the gel. The polarity of the current is reversed for a few moments to cause any DNA actually on the dialysis membrane to move back into the buffer within the bag. The DNA in the buffer is then precipitated with ethanol. 

Nickel of activity comparable to Raney nickel is obtained by reduction of nickel salts, e.g. nickel acetate, with 2 mol of sodium borohydride in an aqueous solution and by washing the precipitate with ethanol [13, 47] Procedure 7, p. 205). Such preparations are designated P-1 or P-2 and can be conveniently prepared in situ in a special apparatus [4] Procedure 2, p. 202). They contain a high percentage of nickel boride, are non-magnetic and non-pyrophoric and can be used for hydrogenations at room temperature and... 

For the recovery and purification of the eluted RNA, add 5 pg t-RNA as a carrier, and phenol- and chloroform-extract the eluate, precipitate with ethanol, and resuspend the pellet in 12 pi DEPC-treated HjO-... 

Oakmoss absolute and tree moss absolute are obtained from tree lichens. Oakmoss absolute is derived from Evernia prunastri (L.) Arch. (Usnaceae), a lichen growing on oak trees. The lichen is first extracted with nonpolar solvents to give a concrete. The waxes are then removed by precipitation with ethanol, leaving an absolute. 

Preparation By extraction of poppy capsules or opium (opium contains 9-14 % morphine depending on the source) with water, precipitation with aqueous Na2C03 solution, washing of the precipitate with ethanol and dissolution in dilute acetic acid (Horner et al. (Knoll), 1977, Trauner et al.,1983, Hudlicky et al.,1996). 

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