[Extraction of drugs. 4. Selective extraction properties of solvents].
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Methods↗
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Extraction rates of marker compounds from rubber closures for parenteral use. II. mechanism of extraction and evaluation of select extraction parameters.
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Diffusion↗
The selective extraction of histones from rye chromatin.
The selective extraction of histones from rye chromatin was studied using three different methods. Extractions with NaCl-phosphate buffers at pH5.5 gave results similar to those already obtained with other types of chromatin. Histone H1 was selectively extracted with 0.6 M NaCl-0.001 M PO4, while the selectivity of dissociation of the other fractions was reduced at higher NaCl concentrations. The use of phosphate-urea buffers at pH5.5 also revealed that the histones were dissociated at the same concentrations as were calf thymus histones. Histone H1 was extracted with 0.5 M PO4-1 M urea; H1, H2A, and H2B were extracted with 0.8 M PO4-2 M urea; and all histones were removed with 0.8 M PO4-5.3 M urea. It was, however, observed that the dissociated rye histones H2A and H2B were unstable in these buffers. This instability was maximum in the presence of 3 M urea, where both histones were absent from the extracted proteins and the residual nucleoproteins. Finally, a solution of 30% ethanol-0.35 M NaCl-6 M urea produced a rye nucleoprotein fraction containing only histone H1.
Animals↗
Application of selective extraction to the study of iron species present in diet and rat gastrointestinal tract contents.
Iron speciation in rodent diet and rat gastrointestinal tract lumen during dietary digestion and absorption was investigated with a novel selective extraction technique. Five Fe fractions were identified, namely exchangeable (soluble in 1 M-magnesium chloride), carbonate-bound (soluble in mild acid), oxide-bound (soluble in hydroxylamine-acetic acid), organic-bound (soluble after treatment with peroxide in nitric acid) and residual. Fe from the pelleted diet was mobilized by rat stomach to the exchangeable fraction, then redistributed to the carbonate- and oxide-bound fractions on passage through the proximal small intestine. In vitro incubation of diet with hydrochloric acid failed to mimic the in vivo effect of the stomach. In vitro neutralization of stomach contents with bicarbonate was found to produce a similar effect on Fe speciation to that seen when diet passed the proximal small intestine in vivo. Comparison of 59Fe speciation in extrinsically labelled diet with endogenous Fe speciation showed that extrinsic labelling does not uniformly label all endogenous species. The experiments suggest that selective extraction may provide a useful approach to the study of Fe species present in diets, in vitro digestions and gastrointestinal contents.
Animals↗
Selective Extraction of Genomic DNA From Animal Tissues Using a Hydrophobic Magnetic Ionic Liquid.
The development of green and efficient methods for genomic DNA extraction from animal tissues is crucial for molecular diagnostics, food traceability, and genetic research. Conventional methods often involve toxic reagents, multiple centrifugation steps, and are time-consuming. In this study, a hydrophobic magnetic ionic liquid (MIL), N-octyl-4-dimethylaminopyridinium hexafluorophosphate MIL ([C8DMAP][PF6]‑Ni MIL), was synthesized and applied for the selective extraction of genomic DNA from various animal tissues. The material exhibited strong paramagnetic behavior, high thermal stability, and excellent hydrophobicity, enabling rapid phase separation under an external magnetic field. A mechanical shaking-assisted extraction method was developed, and key parameters including temperature, time, shaking speed, and [C8DMAP][PF6]-Ni MIL dosage were systematically optimized. The method demonstrated high selectivity for DNA over proteins, RNA, and amino acids, with a maximum recovery rate of 78.06 ± 1.91%. Compared to a commercial DNA extraction kit, the [C8DMAP][PF6]-Ni MIL-based approach provided higher yields from several tissues, including mouse liver, brain, and rabbit lung. Furthermore, the [C8DMAP][PF6]-Ni MIL could be reused for at least six cycles while maintaining extraction efficiency. This work not only provides a high-performance material for DNA extraction, but also demonstrates a sustainable and easily retrievable liquid-phase separation strategy, offering a generalizable platform for complex sample pretreatment.
Animals↗
Selective extraction of Chara actin bundles: identification of actin and two coextracting proteins.
The sub-cortical actin bundles of the alga Chara corallina can be selectively extracted with a low salt solution except when cytochalasin B is present. Proteins with molecular weights of 160000, 43000 and 37000 share this extraction behaviour. While chemical cleavage of the 43000 band indicates that it is actin, the nature of the other proteins is unknown. Although the 37000 protein resembles tropomyosin in molecular weight it lacks tropomyosin's distinctively large change in electrophoretic mobility in the presence of urea.
Actins↗
The assay of 4-hydroxy-3-methoxymandelic acid in urine by HPLC with electrochemical detection using bonded-phase silica sorbents for rapid, simple and selective extraction.
A method is reported for the determination of 4-hydroxy-3-methoxymandelic acid (HMMA) by HPLC with electrochemical detection. The preparation of sample prior to HPLC has been studied and an efficient and selective extraction procedure described. Bonded-phase silica extraction columns and a vacuum manifold were used for the simple and rapid processing of batches of urine samples. Combining a reverse-phase C18 and an anion exchange column ensures selective isolation of HMMA. This simplified greatly the subsequent chromatography. The method was combined into a simple scheme for the routine analysis of urine HMMA, catecholamines and 5-hydroxyindole-3-acetic acid. The HPLC was standardised such that a single mobile phase was used with minor modification for each of the assays.
Chromatography↗
A selective extraction of growth hormone from bovine pituitary gland and its further purification and crystallization.
A highly efficient method for the isolation of bovine growth hormone (GH) is described. The method is based on selective extraction of GH from 15,000 g subcellular sediment of anterior pituitary gland with 130-150 mM NH4HCO3, 1 mM EGTA, pH 7.2-7.4, at 2-6 degrees C for 60 min, purification of the extracted GH by ammonium sulfate fractionation, one-step ion-exchange column chromatography on DEAE-cellulose (or CM-cellulose), and gel filtration on Sephadex G-75. This 2-3 day procedure provides a highly pure hormone in high yield (up to 70-80 mg per 35-40 g of the whole pituitary gland), which can be crystallized by the batch method at a low ionic strength and isoelectric pH.
Ammonium Sulfate↗
A technique for the selective extraction of water-soluble polypeptides from identified neurons of Aplysia californica.
Increasing the osmotic gradient during hypo-osmotic lysis, by pre-treating Aplysia neurons with 100% ethylene glycol, caused the selective extraction of water-soluble, low molecular weight polypeptides from the cells. Specific 3H-labeled polypeptides in the cells R15, R3-13, and the bag cells which were not extracted by exposure of the cells to distilled water "lysis" were effectively solubilized by this procedure. The possible mechanisms and potential uses of this method are discussed.
Animals↗
Selective extraction, concentration, and assay of orthophosphate from microliter quantities of cultured mammalian cells.
A colorimetric procedure is described for determination of orthophosphate (0.2-2.5 nmol) in sample volumes up to 400 microliters. Orthophosphate is selectively extracted (in the form of phosphomolybdate) into an organic solvent mixture (2-methylpropan-1-ol and petroleum spirit) leaving interfering substances, such as labile organic phosphates, in the aqueous phase. Orthophosphate is then back-extracted into a small volume of aqueous sodium hydroxide. By keeping this volume small, orthophosphate from large dilute samples can be concentrated into small volumes and assayed colorimetrically in microcuvettes using the dye malachite green. The procedure is highly reproducible and insensitive to interfering substances, as shown by comparison with a conventional malachite green assay without the solvent extraction.
Animals↗
Effects of selective extraction of histones on template activities of chromatin by use of exogenous DNA and RNA polymerases.
Exogenous DNA and RNA polymerases were used to measure the template activity of DNA in chromatin in isolated thymus nuclei from which lysinerich or arginine-rich histones were selectively extracted. Measurements were on nuclei containing 20-1200 mug of DNA per ml, the distinctions becoming clear at the higher concentrations. Experiments with RNA polymerase showed only moderate increases in template activity upon extraction of histone, although the removal of lysinerich histone had a greater effect than that of arginine-rich histone. DNA polymerase action on nuclei minus lysinerich histone achieved high results, exceeding even those on DNA itself.
Animals↗
Selective extraction of isolated mitotic apparatus. Evidence that typical microtubule protein is extracted by organic mercurial.
Mitotic apparatus isolated from sea urchin eggs has been treated with meralluride sodium under conditions otherwise resembling those of its isolation. The treatment causes a selective morphological disappearance of microtubules while extracting a major protein fraction, probably consisting of two closely related proteins, which constitutes about 10% of mitotic apparatus protein. Extraction of other cell particulates under similar conditions yields much less of this protein. The extracted protein closely resembles outer doublet microtubule protein from sea urchin sperm tail in properties considered typical of microtubule proteins: precipitation by calcium ion and vinblastine, electrophoretic mobility in both acid and basic polyacrylamide gels, sedimentation coefficient, molecular weight, and, according to a preliminary determination, amino acid composition. An antiserum against a preparation of sperm tail outer doublet microtubules cross-reacts with the extract from mitotic apparatus. On the basis of these findings it appears that microtubule protein is selectively extracted from isolated mitotic apparatus by treatment with meralluride, and is a typical microtubule protein.
Amino Acids↗
Glycophorin-enriched vesicles obtained by a selective extraction of human erythrocyte membranes with a non-ionic detergent.
A method is described for isolating glycophorin-enriched vesicles from human erythrocytes by extracting membranes that were incubated for 30 min at 37 degrees C at pH 4.5 and washed at low and high ionic strength with the nonionic detergent Triton X-100. The extracts were 11.8 +/- 2.4 fold enriched in glycophorin and contained 325 +/- 69 microgram sialic acid/mg protein, which represented 61 +/- 16% of the total sialic acid. Upon removal of Triton X-100 one third of the total glycophorin forms glycophorin-enriched vesicles with coextracted, endogenous lipids as shown sedimintation, dextran-density gradient centrifugation, and electron microscopy. Addition of exogenous lipids increased the fraction of glycophorin-enriched vesicles up to 87%. The incorporation of glycophorin in the membrane was shown by hemagglutination inhibition assays using anti-M sera and by the accessibility of glycophorin to trypsin. Freeze-fractured vesicles did not reveal intramembranous particles. The selectivity of the extraction procedure is not simply due to chemical constraints introduced by disulfide cross-linkage of protein component 3, because only 20% of this protein undergo disulfide cross-linking. The selective extraction of glycophorin implies that glycophorin is segregated from protein component 3 and thus from intramembranous particles when erythrocyte membranes have been incubated at pH 4.5. This segregation may precede aggregation of intramembranous particles.
Cell Fractionation↗
Sulfated proteoglycans of rabbit aorta: selective extraction and alternative method for glycosaminoglycan moiety analysis.
Three different solutions containing urea, guanidine hydrochloride, or a detergent mixture were used to extract proteoglycan molecules (PG) metabolically labeled with 35S from normal rabbit aortic tissue. The size distribution of whole sulfated PG and the glycosaminoglycan (GAG) compositions in the three extracts were compared and found to be characteristically determined by the type of solution used for extraction. The spectrum of sulfated PG isolated by each solution was maintained at consecutive extractions of the tissue, even if this was used after another type of solution. The extracts obtained by using the urea- or guanidine-containing solutions contained similar, rather balanced populations of large and small PG, while the detergent-containing buffer was found to preferentially extract smaller, heparan sulfate-rich aortic PG. The selectivity of various extracting solutions could be exploited to obtain preparations enriched in certain types of sulfated PG. On the other hand, one could obtain a larger variety of 35S-labeled PG from the tissue by consecutively using two solutions with different capacities of extraction. The distribution of GAG moieties among PG populations, separated by size chromatography, was investigated by one of the commonly used methods and by a new method. The standard method is based on comparison of the chromatographic profiles of the extract before and after enzymatic digestions, requiring several chromatographic runs for a sample. In the alternative method proposed, the fractions obtained after a single chromatographic separation are adsorbed onto a support membrane. Processing of the whole membrane by GAG-specific, enzymatic treatments allows simultaneous assessment of GAG types in each fraction.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Selective extraction of the DM-20 brain proteolipid.
Brain DM-20 proteolipid was previously shown to be structurally different from the myelin major proteolipid (MMPL). In an attempt to set up a large-scale purification of DM-20, we studied extraction of brain proteolipids with mixtures of methylene chloride containing up to 80% methanol. The CH2Cl2-CH3OH (3:7, vol/vol) mixture is highly selective for the extraction of bovine brain DM-20 compared to MMPL. Purified DM-20 was obtained after chromatography of the extract on methylated Sephadex.
Animals↗
Mitotic apparatus: the selective extraction of protein with mild acid.
The treatment of isolated mitotic apparatus with mild (pH 3) hydrochloric acid results in the extraction of less than 10 percent of its protein, accompanied by the selective morphological disappearance of the microtubules. The same extraction can be shown to dissolve outer doublet microtubules from sperm flagella. A protein with points of similarity to the flagellar microtubule protein is the major component of the extract from mitotic apparatus.
Animals↗
Highly selective extraction of spiralin from the Spiroplasma citri cell membrane with alkyl-N-sulfobetaines.
The extraction of proteins from the membrane of the mollicute (mycoplasma) Spiroplasma citri by sodium N-dodecyl-N,N-dimethyl-3-amino-1-propane sulfonate (SB12) and sodium N-tetradecyl-N,N-dimethyl-3-amino-1-propane sulfonate (SB14) was studied with electrophoretic methods. The membranes were prepared by osmotic lysis of the cells and depleted of the bulk of extrinsic proteins. It was possible to extract up to 35 and 45% of membrane proteins with SB12 and SB14, respectively. Maximal yield was obtained in both cases with detergent concentrations greater than or equal to 5 mumoles/mg of membrane protein. Spiralin, the major protein in the S. citri membrane, was highly selectively solubilized without the loss of antigenicity, with a yield of about 90% with SB12 and close to 100% with SB14, for a detergent concentration greater than or equal to 0.2 M. The degree of selectivity in favour of spiralin was higher with SB12 (purity approximately equal to 70%) than with SB14 (purity approximately equal to 50%). Treatment of the S. citri membrane with high concentrations of SB12 is a simple and fast procedure for partial purification of spiralin. This example shows that, in some cases, it should be possible to modulate the selectivity of the extraction of membrane proteins simply by varying the relative concentration of detergent.
Bacterial Outer Membrane Proteins↗
Cytochemical evaluation of the Guard procedure a regressive staining method for demonstrating chromosomal basic proteins. I. Effects of fixation, blocking reactions, selective extractions, and polyacid "differentiation".
Appropriately fixed preparations stained by a modification of the Guard (1959) reaction for "sex chromatin" display selective staining of interphase chromatin and mitotic or meiotic chromosomes. This is a regressive staining method which seems to depend on the selective displacement of an acidic dye from less basic structures, and retention of the dye at more basic sites. The results obtained with the reaction can be controlled by the length of time that the preparations are "differentiated" in solutions containing phosphomolybdic and phosphotungstic acids (polyacids). After three- or four-hour exposures to polyacid solutions, all chromatin is stained. However, with longer differentiation, "condensed" chromatin can be stained preferentially. Of a number of fixatives investigated, only 10% formalin, ethanol-acetic acid (3:1), and Bouin's solution proved useful. Others resulted in diminished specificity or a total loss of selectivity. The most intense staining was obtained after formalin fixation. Less intense dyebinding was observed after fixation in 3:1 - probably due to extraction of some histone fractions-and the least amount of dye was bound in Bouin's-fixed chromatin - probably due to blockage of arginine residues by picric acid. The reaction was not affected by enzymatic removal of nucleic acids or the extraction of lipids. It was diminished by treatment with trypsin or weak acetylation, and it was completely prevented by strong acetylation, deamination, or extraction of basic proteins with HCl. The results presented suggest that the modified Guard (1959) procedure selectively demonstrates basic nucleoproteins. Further, by the use of regressive differentiation in polyacid solutions, the retention of dye in more condensed chromatin can be favored.
Animals↗