Centrifugation isopycnic. Medical search

A technique used to separate particles according to their densities in a continuous density gradient. The sample is usually mixed with a solution of known gradient materials and subjected to centrifugation. Each particle sediments to the position at which the gradient density is equal to its own. The range of the density gradient is usually greater than that of the sample particles. It is used in purifying biological materials such as proteins, nucleic acids, organelles, and cell types.

Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Process of using a rotating machine to generate centrifugal force to separate substances of different densities, remove moisture, or simulate gravitational effects. It employs a large motor-driven apparatus with a long arm, at the end of which human and animal subjects, biological specimens, or equipment can be revolved and rotated at various speeds to study gravitational effects. (From Websters, 10th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Centrifugation using a rotating chamber of large capacity in which to separate cell organelles by density-gradient centrifugation. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.

Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.

Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)

A polyvinyl polymer of variable molecular weight; used as suspending and dispersing agent and vehicle for pharmaceuticals; also used as blood volume expander.

A member of the alkali metals. It has an atomic symbol Cs, atomic number 50, and atomic weight 132.91. Cesium has many industrial applications, including the construction of atomic clocks based on its atomic vibrational frequency.

The sum of the weight of all the atoms in a molecule.

A commonly used x-ray contrast medium. As DIATRIZOATE MEGLUMINE and as Diatrizoate sodium, it is used for gastrointestinal studies, angiography, and urography.

A nonreducing disaccharide composed of GLUCOSE and FRUCTOSE linked via their anomeric carbons. It is obtained commercially from SUGARCANE, sugar beet (BETA VULGARIS), and other plants and used extensively as a food and a sweetener.

Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.2.

Tungsten hydroxide oxide phosphate. A white or slightly yellowish-green, slightly efflorescent crystal or crystalline powder. It is used as a reagent for alkaloids and many other nitrogen bases, for phenols, albumin, peptone, amino acids, uric acid, urea, blood, and carbohydrates. (From Merck Index, 11th ed)

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

An organization of cells into an organ-like structure. Organoids can be generated in culture. They are also found in certain neoplasms.

A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured. Such rupture is supposed to be under metabolic (hormonal) control. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

A class of enzymes that catalyze the conversion of a nucleotide and water to a nucleoside and orthophosphate. EC 3.1.3.-.

A solute for density gradient centrifugation offering higher maximum solution density without the problems of increased viscosity. It is also used as a resorbable, non-ionic contrast medium.

A series of steps taken in order to conduct research.

A glycoside obtained from Digitalis purpurea; the aglycone is digitogenin which is bound to five sugars. Digitonin solubilizes lipids, especially in membranes and is used as a tool in cellular biochemistry, and reagent for precipitating cholesterol. It has no cardiac effects.

Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.

Any member of the class of enzymes that catalyze the cleavage of the substrate and the addition of water to the resulting molecules, e.g., ESTERASES, glycosidases (GLYCOSIDE HYDROLASES), lipases, NUCLEOTIDASES, peptidases (PEPTIDE HYDROLASES), and phosphatases (PHOSPHORIC MONOESTER HYDROLASES). EC 3.

Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.

Process of growing viruses in live animals, plants, or cultured cells.

Condensed areas of cellular material that may be bounded by a membrane.

A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.

Electron-dense cytoplasmic particles bounded by a single membrane, such as PEROXISOMES; GLYOXYSOMES; and glycosomes.

Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.

Proteins conjugated with nucleic acids.

The rate dynamics in chemical or physical systems.

A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.

The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.

Enzymes that catalyze the hydrolysis of N-acylhexosamine residues in N-acylhexosamides. Hexosaminidases also act on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES.

Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.

Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.

Established cell cultures that have the potential to propagate indefinitely.

A flavoprotein containing oxidoreductase that catalyzes the dehydrogenation of SUCCINATE to fumarate. In most eukaryotic organisms this enzyme is a component of mitochondrial electron transport complex II.

Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.

Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.

An enzyme that catalyzes the oxidative deamination of naturally occurring monoamines. It is a flavin-containing enzyme that is localized in mitochondrial membranes, whether in nerve terminals, the liver, or other organs. Monoamine oxidase is important in regulating the metabolic degradation of catecholamines and serotonin in neural or target tissues. Hepatic monoamine oxidase has a crucial defensive role in inactivating circulating monoamines or those, such as tyramine, that originate in the gut and are absorbed into the portal circulation. (From Goodman and Gilman's, The Pharmacological Basis of Therapeutics, 8th ed, p415) EC 1.4.3.4.

A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).

The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.

Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.

Deoxyribonucleic acid that makes up the genetic material of viruses.

Condition wherein the force of gravity is greater than or is increased above that on the surface of the earth. This is expressed as being greater than 1 g.

Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.

The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

High molecular weight mucoproteins that protect the surface of EPITHELIAL CELLS by providing a barrier to particulate matter and microorganisms. Membrane-anchored mucins may have additional roles concerned with protein interactions at the cell surface.

Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.

A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17.

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.

Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.

Cancers or tumors of the LARYNX or any of its parts: the GLOTTIS; EPIGLOTTIS; LARYNGEAL CARTILAGES; LARYNGEAL MUSCLES; and VOCAL CORDS.

A process of separating particulate matter from a fluid, such as air or a liquid, by passing the fluid carrier through a medium that will not pass the particulates. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)

Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)

Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.

A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.

Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.

A group of lysosomal proteinases or endopeptidases found in aqueous extracts of a variety of animal tissues. They function optimally within an acidic pH range. The cathepsins occur as a variety of enzyme subtypes including SERINE PROTEASES; ASPARTIC PROTEINASES; and CYSTEINE PROTEASES.

Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.

Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)

A suborder of PRIMATES consisting of six families: CEBIDAE (some New World monkeys), ATELIDAE (some New World monkeys), CERCOPITHECIDAE (Old World monkeys), HYLOBATIDAE (gibbons and siamangs), CALLITRICHINAE (marmosets and tamarins), and HOMINIDAE (humans and great apes).

The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.

Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.

Glycoproteins which have a very high polysaccharide content.

Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.

The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)

The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.

A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)

Proteins found in any species of virus.

An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.

Presence of warmth or heat or a temperature notably higher than an accustomed norm.

Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.

Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)

The process by which a DNA molecule is duplicated.

Elements of limited time intervals, contributing to particular results or situations.

Ribonucleic acid that makes up the genetic material of viruses.

Protein components on the surface of LIPOPROTEINS. They form a layer surrounding the hydrophobic lipid core. There are several classes of apolipoproteins with each playing a different role in lipid transport and LIPID METABOLISM. These proteins are synthesized mainly in the LIVER and the INTESTINES.

Proteins found in any species of bacterium.

Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.

Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.

Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.

Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.

The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.

Lipid-protein complexes involved in the transportation and metabolism of lipids in the body. They are spherical particles consisting of a hydrophobic core of TRIGLYCERIDES and CHOLESTEROL ESTERS surrounded by a layer of hydrophilic free CHOLESTEROL; PHOSPHOLIPIDS; and APOLIPOPROTEINS. Lipoproteins are classified by their varying buoyant density and sizes.

Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.

The formation of a solid in a solution as a result of a chemical reaction or the aggregation of soluble substances into complexes large enough to fall out of solution.

A type of ion exchange chromatography using diethylaminoethyl cellulose (DEAE-CELLULOSE) as a positively charged resin. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Triiodo-substituted derivatives of BENZOIC ACID.

Purification of gibberellic acid-induced lysosomes from wheat aleurone cells. (1/213)

Using isopycnic density gradient centrifugation, lysosomes were concentrated in a single region of a sucrose-Ficoll gradient (p = 1-10 g cm-3), well separated from most other cell organelles. Gibberellic acid-induced lysosomes were found to be rich in alpha-amylase and protease but not ribonuclease. The lysosomal band also contained a majority of the NADH2-cytochrome c reductase, a marker enzyme for endoplasmic reticulum, found in the gradient. Examination of electron micrographs revealed that a purified band of lyosomes contained at least 3 vesicle types, ranging in size from 0-1 to 0-5 mum. The significance of these findings to proposed mechanisms of action of gibberellic acid is discussed. (+info)

Lectins as membrane components of mitochondria from Ricinus communis. (2/213)

1. Mitochondria were isolated from developing endosperm of Ricinus communis and were fractionated into outer membrane and inner membrane. The relative purity of the two membrane fractions was determined by marker enzymes. The fractions were also examined by negative-stain electron microscopy. 2. Membrane fractions were sequentially extracted in the following way. (a) Suspension in 0.5M-potassium phosphate, pH7.1; (b)suspension in 0.1M-EDTA (disodium salt)/0.05M-potassium phosphate, pH7.1; (c) sonication in 0.05M-potassium phosphate, pH7.1;(d)sonication in aq. Triton X-100 (0.1%). The membranes were pelleted by centrifugation at 100 000g for 15 min, between each step. Agglutination activity in the extracts was investigated by using trypsin-treated rabbit erythrocytes. 3. The addition of lactose to inner mitochondrial membrane resulted in the solubilization of part of the lectin activity, indicating that the protein was attached to the membrane via its carbohydrate-binding site. Pretreatment of the membranes with lactose before tha usual extraction procedure showed that lactose could extract lectins that normally required more harsh treatment of the membrane for solubilization. 4. Lectins extracted from inner membranes were purified by affinity chromatography on agarose gel. Polyacrylamide-gel electrophoresis of purified samples in sodium dodecyl sulphate indicated that at least part of the lectin present in inner mitochondrial membrane was identical with the R. communis agglutinin of mol.wt. 120 000. (+info)

Transduction-like gene transfer in the methanogen Methanococcus voltae. (3/213)

Strain PS of Methanococcus voltae (a methanogenic, anaerobic archaebacterium) was shown to generate spontaneously 4.4-kbp chromosomal DNA fragments that are fully protected from DNase and that, upon contact with a cell, transform it genetically. This activity, here called VTA (voltae transfer agent), affects all markers tested: three different auxotrophies (histidine, purine, and cobalamin) and resistance to BES (2-bromoethanesulfonate, an inhibitor of methanogenesis). VTA was most effectively prepared by culture filtration. This process disrupted a fraction of the M. voltae cells (which have only an S-layer covering their cytoplasmic membrane). VTA was rapidly inactivated upon storage. VTA particles were present in cultures at concentrations of approximately two per cell. Gene transfer activity varied from a minimum of 2 x 10(-5) (BES resistance) to a maximum of 10(-3) (histidine independence) per donor cell. Very little VTA was found free in culture supernatants. The phenomenon is functionally similar to generalized transduction, but there is no evidence, for the time being, of intrinsically viral (i.e., containing a complete viral genome) particles. Consideration of VTA DNA size makes the existence of such viral particles unlikely. If they exist, they must be relatively few in number;perhaps they differ from VTA particles in size and other properties and thus escaped detection. Digestion of VTA DNA with the AluI restriction enzyme suggests that it is a random sample of the bacterial DNA, except for a 0.9-kbp sequence which is amplified relative to the rest of the bacterial chromosome. A VTA-sized DNA fraction was demonstrated in a few other isolates of M. voltae. (+info)

Detection of serum proteins in the electrophoretic patterns of total proteins of mycoplasma cells. (4/213)

The contamination of mycoplasma cell preparations by serum proteins originating from culture medium was studied. A. laidlawii and M. arthritidis cells were grown in the presence of [14C]-aminoacids, and the cells were washed with 0-9% NaC1 by threefold centrifugation. Total proteins of the washed cells were analysed by SDS gel electrophoresis. Coomassie-stained electrophoretic patterns were compared with autoradiographs of the same gels. The stained electrophoretic pattern of washed A. laidlawii grown without serum was identical with autoradiographs of the same cells grown without or with serum. That of washed A. laidlawii grown with serum differed from the corresponding autoradiography by the presence of extra protein bands I, II, III, and IV with molecular weights of over 160,000, 80,000-87,000, 55,000 and 25,000, respectively. The same extra bands were found in stained electrophoretic patterns of washed: (a) A. laidlawii cells grown without serum and mixed with serum in the stationary phase, (b) M. arthritidis cells, as compared with their autoradiographs, (c) serum precipitate. The bands III and IV may be due to the heavy and light chains of gamma-globulin, the band II might belong to transferrin or to some component of complement. Acidification of serum to pH 5 brought about 100-fold rise of amount of serum precipitate, the number of bands in the electrophoretic pattern of the precipitate being also increased. Stained electrophoretic patterns of cells purified by twofold centrifugation in step sucrose density gradient (1-20-1-27 g./cm.3 for A. laidlawii, and 1-15-1-25 for M. arthritidis) contained no extra bands and matched completely with their autoradiographs. It was concluded that contamination of washed mycoplasma cells by serum proteins is mainly due to co-precipitation of aggregated serum proteins together with cells during centrifugation rather than to adsorption of serum proteins on the cell surface. (+info)

A study of the intracellular and secreted forms of the MUC2 mucin from the PC/AA intestinal cell line. (5/213)

In this study we present data on the entire population of MUC2 molecules secreted from and within the cell layer of an intestinal cell line. The molecular size distribution of the extracted molecules and their reactivity with two different MUC2 polypeptide antibodies indicated the presence of precursor and mature forms of the mucin. Oligomerized forms of the mucin were found in both the cell layer and medium; however, precursor forms were confined to the cell layer. Isopycnic density gradient centrifugation gave good resolution of mature and precursor forms of MUC2 as assessed by agarose gel electrophoresis. Three different populations of MUC2 were identified: one at low density (>1.3 g/ml) containing the N-glycosylated, non-O-glycosylated polypeptide; a second at intermediate density (1.3-1.35 g/ml) which may represent partially O-glycosylated intermediates; and a third at high density (1.36-1.48 g/ml) containing the mature MUC2 mucins. Rate-zonal centrifugation and agarose electrophoretic analysis of the low-density fraction indicated that the N-glycosylated MUC2 polypeptide was present as putative monomer and dimer/oligomer species. The combination of isopycnic density gradient centrifugation with agarose electrophoresis provides a new and simple approach that allows us to follow the MUC2 gene product from polypeptide through to the mature glycosylated mucin. (+info)

Isopycnic sedimentation of DNA in metrizamide: the effect of low concentrations of ions on buoyant density and hydration. (6/213)

Metrizamide, an inert, non-ionic organic compound, dissolves in water to give a dense solution in which DNA bands isopycnically at a density corresponding to that of fully hydrated DNA. Density-gradient centrifugation in solutions of metrizamide has been used to determine the effects of very dilute solutions of salts on the buoyant density of native and denatured DNA. It has been shown that the buoyant density of DNA is dependent on both the counter-cation and the anion present. Interpretation of the data in terms of the degree of hydration of the macromolecule indicates that (i), NaDNA is more highly hydrated than CsDNA; and (ii), the hydration of NaDNA varies with anion in the order sulphate< fluoride< chloride< bromide< iodide. It is suggested that isopycnic centrifugation in metrizamide is a simple method for determining the effects of salts (and other small molecules) on the hydration of nucleic acids under conditions of high ratios of salt to DNA (> 5 x 10(3) moles/mole) while high (0.999) water activity is maintained. (+info)

Fractionation and characterization of satellite DNAs of the kangaroo rat (Dipodomys ordii). (7/213)

Nuclear DNA from liver cells of the kangaroo rat species Dipodomysordii was fractionated and characterized with the aid of buoyant density gradients in neutral and alkaline CsCl and in Ag(+)-Cs(2)SO(4). More than one-half of the DNA was present in three density satellites, a greater proportion than in any other species yet reported; the purified satellite DNAs were denser than principal DNA. All satellite fractions revealed sharp isopycnic bands and narrow denaturation profiles. Two had identical buoyant densities but differed substantially in T(m), base composition, and reassociation kinetics. In alkaline CsCl all three satellites, as well as a shoulder of intermediate repetitive DNA on the heavy side of the principal band, revealed unique strand densities. The most highly repetitive satellite was unusually rich in (G + C) and contained 6.7% of 5-methylcytosine. A survey of internal organs and spermatozoa of an adult male revealed no significant differences in distribution of the satellites among tissues. (+info)

Human immunodeficiency virus type 1 virion density is not determined by nucleocapsid basic residues. (8/213)

The human immunodeficiency virus type 1 (HIV-1) Gag polyprotein is sufficient for assembly and release of virion-like particles from the plasma membrane. To promote assembly, the Gag polyprotein must polymerize to form a shell that lines the inner membrane of nascent virions. Several techniques have been used to functionally map the domain required for Gag polymerization (the I domain). Among these methods, isopycnic centrifugation has been used under the assumption that changes in virion density reflect impairment in Gag-Gag interaction. If virion density is determined by efficient Gag-Gag interaction, then mutation of basic residues in the nucleocapsid (NC) domain should disrupt virion density, since these residues constitute the I domain. However, we have previously shown that simultaneous disruption of up to 10 HIV-1 NC basic residues has no obvious effect on virion density. To rule out the possibility that HIV-1 NC basic residues other than those previously mutated might be important for virion density, mutations were introduced at the remaining sites and the ability of these mutations to affect Gag-Gag interaction and virion density was analyzed. Included in our analysis is a mutant in which all NC basic residues are replaced with alanine. Our results show that disruption of HIV-1 NC basic residues has an enormous effect on Gag-Gag interaction but only a minimal effect on the density of those virions that are still produced. Therefore, the determinants of the I domain and of virion density are genetically distinguishable. (+info)

Variations of this include Isopycnic centrifugation, Differential centrifugation, and Sucrose gradient centrifugation. A blood ...

https://en.wikipedia.org/wiki/Density_gradient

Neuburger M, Journet EP, Bligny R, Carde JP, Douce R (1982). "Purification of plant mitochondria by isopycnic centrifugation in ...

https://en.wikipedia.org/wiki/Roland_Douce

Another applicable technique is cofractionation in sucrose (or other material) gradients using isopycnic centrifugation. While ...

https://en.wikipedia.org/wiki/Protein

H2 Caesium chloride is widely used in centrifugation in a technique known as isopycnic centrifugation. Centripetal and ... Caesium chloride is widely used medicine structure in isopycnic centrifugation for separating various types of DNA. It is a ...

https://en.wikipedia.org/wiki/Caesium_chloride

It is a white water-soluble solid that is used to prepare dense aqueous solutions for use in isopycnic (or "density-gradient") ... centrifugation. It is isostructural with potassium salt. Coordination sphere of one of two types of Cs+ site in Cs2SO4. ...

https://en.wikipedia.org/wiki/Caesium_sulfate

... into them can be separated from biomarkers containing the more naturally abundant lighter isotope by isopycnic centrifugation. ... As the biomarker, DNA with 13C is then separated from DNA with 12C by centrifugation. Sequencing the DNA identifies which ...

https://en.wikipedia.org/wiki/Stable-isotope_probing

Another applicable technique is cofractionation in sucrose (or other material) gradients using isopycnic centrifugation.[45] ...

https://fa.wikipedia.org/wiki/پروتئین?match=en

... used to separate certain organelles from whole cells for further analysis of specific parts of cells Isopycnic centrifugation, ... Centrifugation Methods. John Wiley & Sons, Mar 4, 2004, pp. 247-267. Frothingham, R (February 1999). "Centrifugation without a ... There are various types of centrifugation: Differential centrifugation, often ... Another potential hazard is the aerosolization of hazardous samples during centrifugation. To prevent contamination of the ...

https://en.wikipedia.org/wiki/Laboratory_centrifuge

... centrifugation, density gradient MeSH E05.181.724.336.253 - centrifugation, isopycnic MeSH E05.181.724.336.336 - centrifugation ... centrifugation, density gradient MeSH E05.196.941.336.253 - centrifugation, isopycnic MeSH E05.196.941.336.419 - centrifugation ...

https://en.wikipedia.org/wiki/List_of_MeSH_codes_(E05)

... centrifugation refers to a method wherein a density gradient is either pre-formed or forms during high speed ... An isopycnic surface is a surface of constant density inside a fluid. Isopycnic surfaces contrast with isobaric or isothermal ... isopycnic centrifugation Isosteric v t e v t e. ... Isopycnic surfaces are sometimes referred to as "iso-density" ... Isopycnic typically describes surfaces, not processes. Unless there is a flux of mass into or out of a control volume, a ...

https://en.wikipedia.org/wiki/Isopycnic

... (also isopycnic centrifugation or equilibrium density-gradient centrifugation) uses the concept ... Isopycnic Satellite DNA Schildkraut, Carl L.; Marmur, Julius; Doty, Paul (1962). "Determination of the base composition of ...

https://en.wikipedia.org/wiki/Buoyant_density_centrifugation

Main articles: Differential centrifugation, Isopycnic centrifugation, and ultracentrifugation. Ultracentrifugation makes use of ... Differential CentrifugationEdit. Differential Centrifugation is a type of centrifugation in which one selectively spins down ... "Centrifugation Basics". Sigma-Aldrich. Retrieved 10 May 2016.. *^ Article on "Centrifugation" retrieved on 15 October 2013 from ... Density Gradient CentrifugationEdit. Density gradient centrifugation is considered one of the more efficient methods of ...

https://en.m.wikipedia.org/wiki/Centrifugation

Skinner, Dorothy M.; Beattie, Wanda G. (September 1974). "Characterization of a pair of isopycnic twin crustacean satellite ... Polymerase chain reaction Buoyant density centrifugation Gene expression Microsatellite Triple-stranded DNA Z-DNA Stem-loop ...

https://en.wikipedia.org/wiki/Satellite_DNA

Another applicable technique is cofractionation in sucrose (or other material) gradients using isopycnic centrifugation.[49] ...

https://en.m.wikipedia.org/wiki/Protein_synthesis

... and 24 Mycoplasma species by a new method that combines a micro-scale preparation of DNA with isopycnic gradient centrifugation ... Determination of the Guanine-Plus-Cytosine Content of Mollicutes by Isopycnic Gradient Centrifugation * H. Kirchhoff and J. ... and 24 Mycoplasma species by a new method that combines a micro-scale preparation of DNA with isopycnic gradient centrifugation ...

https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-37-4-454

... isopycnic? Find out information about Centrifugation, isopycnic. A line on a chart connecting all points of equal or constant ... Of equal or constant density, with respect to either space or time Explanation of Centrifugation, isopycnic ... Related to Centrifugation, isopycnic: Differential centrifugation, density gradient centrifugation isopycnic. [¦ī·sō¦pik·nik] ( ... isopycnic. (redirected from Centrifugation, isopycnic). Also found in: Dictionary. ...

https://encyclopedia2.thefreedictionary.com/Centrifugation%2C+isopycnic

Isopycnic Centrifugation Principal. by Bill Williams January 20, 2018, 11:04 am. 1.5k Views ... For isopycnic centrifugation, it is needed mostly for maximum density. There is no compound which can possess all the traits ... While using isopycnic centrifugation, the particles can never sediment to the bottom of the tube regardless of the time. ... Isopycnic centrifugation is also known as equilibrium or buoyant separation. It is the process of separating particles or ...

https://hugecount.com/science/isopycnic-centrifugation-principal/

Isopycnic centrifugation* XPB* Gene cassette* Ori (genetics)* RpoB* Eukaryotic chromosome structure* Eukaryotic intergenic DNA* ...

https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/images/176/17604.png.htm

The text then reviews isopycnic centrifugation in ionic media and analytical centrifugation. Topics include separation by ... Isopycnic Zonal Experiments Time to Reach Equilibrium Resolution of Isopycnic Zones Interaction Between Solutes in Isopycnic ... 7 Isopycnic Centrifugation in Non-Ionic Media. General Techniques Density-Gradient Solutes Monosaccharides and Disaccharides ... 6 Isopycnic Centrifugation in Ionic Media Basic Procedures Optimum Design of Buoyant Density-Gradient Separations Equilibrium ...

https://www.elsevier.com/books/centrifugal-separations-in-molecular-and-cell-biology/birnie/978-0-408-70803-6

Isopycnic centrifugation. *Sucrose gradient centrifugation. Types and uses of centrifuges. There are basically four types of ... Industrial Centrifugation Technology. New York, NY: McGraw-Hill. ISBN 0070371911. *Regel, Liya L. and William R. Wilcox. 2001. ... Centrifugation is a process that involves the use of the centrifugal force for the separation of mixtures, used in industry and ... Protocols for centrifugation typically specify the amount of acceleration to be applied to the sample, rather than specifying a ...

https://www.newworldencyclopedia.org/entry/Centrifugation

Buoyant density centrifugation (also isopycnic centrifugation or equilibrium density-gradient centrifugation) uses the concept ... Isopycnic Satellite DNA Schildkraut, Carl L.; Marmur, Julius; Doty, Paul (1962). "Determination of the base composition of ...

https://en.wikipedia.org/wiki/Buoyant_density_centrifugation

Isopycnic gradient centrifugation of virus. Huh-7.5 cells infected with HAV were cultured in DMEM medium supplemented with 10% ... B) Concentrated supernatant fluids from HAV-infected cells were subjected to isopycnic gradient centrifugation, and individual ... isopycnic gradient fractions containing eHAV were subjected to a second round of centrifugation in rate-zonal gradients (25). ... Rate-zonal centrifugation. Samples were loaded onto a preformed 6%-18% iodixanol gradient and centrifuged at 250,000 g in a ...

https://www.jci.org/articles/view/77527

Centrifugation is the use of the centrifugal forces generated in a spinning rotor to separate biological particles, such as ... isopycnic centrifugation separates particles on the basis of their density. The choice of centrifugation method depends on the ... Figure 2. Differential centrifugation of a homogenate: (a) before centrifugation and (b) after centrifugation. ... centrifugation and isopycnic centrifugation. The first two methods separate particles primarily on the basis of size while ...

http://www.els.net/WileyCDA/ElsArticle/refId-a0002704.html

Isopycnic gradient centrifugation of EMVs. EMVs were purified from differentiated C2C12 cells. C2C12 cells were seeded onto T- ... and during substantial and lengthy procedures which included isopycnic gradient centrifugation and Exoquick-TC precipitation ( ... After centrifugation and washing in 70% ethanol, the DNA pellet was air-dried at room temperature for 20 minutes. The pellet ... C2C12 cell cultures infected with eGFP-CVB3 were collected at day 3 PI and purified by Isopycnic gradient centrifugation. ...

https://www.prolekare.cz/casopisy/plos-pathogens/2014-4/coxsackievirus-b-exits-the-host-cell-in-shed-microvesicles-displaying-autophagosomal-markers-53540

Centrifugation, Isopycnic. A technique used to separate particles according to their densities in a continuous density gradient ... Centrifugation, Density Gradient. Separation of particles according to density by employing a gradient of varying densities. At ... The sample is usually mixed with a solution of known gradient materials and subjected to centrifugation. Each particle ...

https://www.bioportfolio.com/resources/pmarticle/2154983/Diagnostic-value-of-longitudinal-flow-gradient-for-the-presence-of-haemodynamically-significant.html

... infectious virus was separated from host cell membranes and proteins by density equilibrium centrifugation in gradients of ... Centrifugation, Density Gradient * Centrifugation, Isopycnic * Chromatography, Gel * Colloids * HeLa Cells * Humans * Measles ...

https://pubmed.ncbi.nlm.nih.gov/6323505/?dopt=Abstract

Isopycnic centrifugation refers to a method wherein a density gradient is either pre-formed or forms during high speed ... An isopycnic surface is a surface of constant density inside a fluid. Isopycnic surfaces contrast with isobaric or isothermal ... isopycnic centrifugation Isosteric v t e v t e. ... Isopycnic surfaces are sometimes referred to as "iso-density" ... Isopycnic typically describes surfaces, not processes. Unless there is a flux of mass into or out of a control volume, a ...

https://en.wikipedia.org/wiki/Isopycnic

Analytical fractionation by isopycnic density gradient centrifugation of LDM. Each fraction was tested for its content p97, ... Low-density microsomes were separated by isopycnic density gradient centrifugation on linear sucrose gradients (d1.05-1.25). ...

https://www.pnas.org/content/97/25/13637?ijkey=8c2a2ad64aaa2e018d1100f52fe65d5f590a202a&keytype2=tf_ipsecsha

Types of centrifugation. Differential centrifugation. Rate-zonal centrifugation. Isopycnic centrifugation. Differential ... Isopycnic centrifugation. Mostly used to separate nucleic acids.. Based solely on the density of the particles.. Unaffected by ... Rate-zonal centrifugation. Centrifugation medium is characterized by a positive increment in density density gradient.. Sample ... Centrifugation. The separation of subcellular fractions is achieved by centrifugation.. Particles of different density, size, ...

http://www.protocol-online.org/forums/topic/3359-subcellular-fractionation/

Isopycnic centrifugation.The isopycnic centrifugation of the RNA in cesium trifluoroacetate (CsTFA; GE Healthcare) gradients ... RNA was extracted from root material and rhizosphere soil and subjected to cesium gradient centrifugation followed by 16S rRNA ... Labeled and unlabeled microbial RNA can be separated by density gradient centrifugation in order to identify the microbial ...

https://aem.asm.org/content/81/6/2244

Another applicable technique is cofractionation in sucrose (or other material) gradients using isopycnic centrifugation.[45] ...

https://en.wikipedia.org/wiki/Bacterial_protein

1966) Isopycnic centrifugation for the isolation of DNA strands coding for ribosomal RNA. Science 152(3721):509-512. ... Lower) Centrifugation analysis in isopycnic density gradient of plasmid DNA (pSC112) isolated from an E. coli clone expressing ... coli DNA by buoyant density differences during isopycnic centrifugation, as well as by fragment size during agarose gel ... The number of fragments would be few enough to separate them by centrifugation, enabling their use in DNA-DNA hybridization ...

https://www.pnas.org/content/110/39/15521.full?sid=8b77d212-390e-4470-9e34-991e77479d4c

Categories: Centrifugation, Isopycnic Image Types: Photo, Illustrations, Video, Color, Black&White, PublicDomain, ...

https://phil.cdc.gov/AdvancedSearchResults.aspx?Search=Centrifugation,+Isopycnic&parentid=5731&catid=5733

The resulting linear plasmid was purified by isopycnic centrifugation at 58,000 rpm, 20°C for 24 hours with a CsCl gradient ... The final product was purified using isopycnic centrifugation. The fraction containing the closed circular form of plasmid was ... 5E). The final site-specific circular plasmid, pGLuc9temG+ICL, was purified by isopycnic ultracentrifugation (Fig. 5f). With ...

https://cancerres.aacrjournals.org/content/73/14/4451

Isolation of enriched cardiomyocyte populations by isopycnic centrifugation is illustrated in Examples 4 and 9. Starting with ... After centrifugation, cells on top of the Percoll™ (fraction I) and a layer of cells in the interface of two layers of Percoll ... Four-Phase Centrifugation Separation Method. Cardiomyocytes were generated from hES cells of the H7 line by forming embryoid ... For example, cardiomyocytes are collected by centrifugation at 1000 rpm for 5 min, and then mRNA is prepared from the pellet by ...

http://www.google.com/patents/US7732199?dq=5958006

Isopycnic centrifugation in cesium trifluoroacetate yielded RNA with the lowest possible amounts of contaminating DNA. This ...

https://www.ncbi.nlm.nih.gov/pubmed/7516345?dopt=Abstract

Separation of sub-cellular components and viruses by combined rate- and isopycnic-zonal centrifugation. Natl Cancer Inst Monogr ... Purification of large quantities of influenza virus by density gradient centrifugation. J Virol. 1967;1:1207-6.PubMed ... When the sedimentation coefficients of then-known viruses were plotted against their isopycnic banding densities, nearly all ... The initial choice is between filtration and centrifugation. Seawater contains little contaminating material of the size and ...

https://wwwnc.cdc.gov/eid/article/9/7/03-0004

Isopycnic centrifugation and gradient fractionation was done as previously described (Glaubitz et al., 2009; Kleindienst et al ... and rRNA-based stable isotope probing by fractionation and quantitative analysis of isopycnic centrifugation gradients. Environ ... 2014) with 750 ng of total RNA loaded into each gradient and collection of 12 RNA fractions after centrifugation. ...

https://www.frontiersin.org/articles/10.3389/fmicb.2016.01524/full

Viruses were gradient-purified by CsCl isopycnic centrifugation, dialyzed against HEPES-buffered saline (in mm: 10 HEPES, 140 ... Cytoplasmic proteins were obtained by centrifugation at 12,000 rpm for 15 min at 4°C. The proteins (50 μg) were separated on ...

https://www.jneurosci.org/node/354587.full.print

Organelles were separated by isopycnic centrifugation at 116,000 g for 2 h in a NVT65 rotor (Beckman Coulter). Fractions of 1 ... Peroxisomes were isolated from 20kgP fractions of Pex25-pA and Yor084-pA strains by isopycnic centrifugation. The gradients ... Organelles in the 20kgP were separated by isopycnic centrifugation. Proteins were identified in each fraction by Western ... The membranes and associated components (Ti8P) were harvested by centrifugation. Chimeras of Pex25p and the membrane proteins ...

http://jcb.rupress.org/content/158/2/259

Another applicable technique is cofractionation in sucrose (or other material) gradients using isopycnic centrifugation.[45] ...

https://fa.wikipedia.org/wiki/%D9%BE%D8%B1%D9%88%D8%AA%D8%A6%DB%8C%D9%86?match=en

Isopycnic Separation of Cells and Cell Organelles by Centrifugation in Modified Colloidal Silica Gradients ...

https://link.springer.com/book/10.1007%2F978-1-4684-0820-1?error=cookies_not_supported&code=6ce2f689-0f58-4e0f-afb8-2e0eaf112a55

Subcellular distribution of [125I]gelonin was established after differential and isopycnic centrifugation. Fractions were ...

http://www.biomedsearch.com/cluster/14/Lipid-Metabolism/sub-36-p8.html

These organelles were subfractionated by isopycnic centrifugation on iso-osmotic Percoll gradients. A lysosomal peak was ... fold purification of pig thyroid lysosomes was achieved by using a new tissue-disruption procedure and isopycnic centrifugation ... The lysosomal peak, from which Percoll was removed by centrifugation, was taken as the purified lysosome fraction (L). ...

https://portlandpress.com/biochemj/article-abstract/232/2/529/20454/Isolation-of-pig-thyroid-lysosomes-Biochemical-and?redirectedFrom=fulltext

After concentration by ultrafiltration and sedimentation, infectious virus was separated from host cell membranes and proteins by density equilibrium centrifugation in gradients of colloidal silica. (nih.gov)
These organelles were subfractionated by isopycnic centrifugation on iso-osmotic Percoll gradients. (portlandpress.com)
Enhanced sensitivity of DNA- and rRNA-based stable isotope probing by fractionation and quantitative analysis of isopycnic centrifugation gradients. (semanticscholar.org)
The possibility of differentiating between chromaffin vesicles with different catecholamine contents was tested by studying the distribution of rabbit adrenal dopamine β-hydroxylase (EC 1.14.21) and catecholamines, and the buoyant densities of the catecholamine storage vesicles after isopycnic centrifugation of crude storage vesicle fractions in sucrose density gradients. (aspetjournals.org)
Using serial isopycnic centrifugation on sucrose gradients, we generated separate apical and basolateral plasma membrane vesicles. (elsevier.com)
Homogenates made from the mucosa of the guinea pig small intestine were fractionated in a zonal rotor by rate and isopycnic centrifugation in sucrose gradients. (athabascau.ca)
Using high-performance liquid chromatography to quantify the various metabolites and isopycnic centrifugation of tubule-derived post-nuclear supernates in linear sucrose gradients to resolve various subcellular organelles, the subcellular sites of metabolism of these drugs were examined. (aspetjournals.org)
The Ca2+- or Mg2+-activated ATPase from rat liver plasma membrane was partly purified by treatments with sodium cholate and lysophosphatidylcholine, and by isopycnic centrifugation on sucrose gradients. (eurekamag.com)
Successful separation of the ¹⁴N- (control) and ¹⁵N-RNA was achieved for both pure and mixed communities using isopycnic caesium trifluoroacetate (CsTFA) gradients in an ultracentrifuge. (nzresearch.org.nz)
After growing the mixed culture with ¹⁵N₂ as the sole nitrogen source, the labelled RNA was extracted and fractionated using isopycnic centrifugation in CsTFA gradients. (nzresearch.org.nz)
Covalently closed circular DNA molecules were isolated from Plasmodium falciparum total DNA by isopycnic centrifugation in CsCl gradients containing either ethidium bromide or 2',6-diamidino-2-phenylindole. (lancs.ac.uk)
Importantly, preparative ultracentrifugation reaches the g-force necessary for timely separation of biological macromolecule samples to their isopycnic point in density gradients. (pharmpro.com)

subtypes from Blastocystis cyst excreters, 1,000 fecal samples from patients suspected of enteroparasitic disease were scored for stool consistency, submitted to xenic in vitro culture (XIVC), formol ethyl acetate concentration (FECT) with subsequent isopycnic centrifugation, and polymerase chain reaction (PCR) with subtype (ST) analysis. (ajtmh.org)
Ribosome removal from rough membranes and subsequent isopycnic centrifugation resulted in a shift in the buoyant density of the ribophorin I-containing membranes. (rupress.org)

This is how the authors separated the two membranes: they turned the cells into spheroplasts by treating them with lysozyme, then lysed these by an osmotic shock, homogenized the particulate fraction, and layered it on a sucrose gradient for high speed centrifugation. (asmblog.org)
Fractionation of E. coli membranes by isopycnic centrifugation on a sucrose gradient. (asmblog.org)
4. Subcellular fractionation of four PH1 livers by sucrose gradient isopycnic centrifugation demonstrated a complete absence of peroxisomal AGT activity. (clinsci.org)
Sucrose gradient centrifugation studies found ribophorin I to be included only in fractions containing rough membranes and excluded from smooth ones that, on the basis of the distribution of BiP, included smooth ER. (rupress.org)

Isopycnic centrifugation is also known as equilibrium or buoyant separation. (hugecount.com)
Buoyant density gradient centrifugation in a continuous gradient. (els.net)
Buoyant density centrifugation (also isopycnic centrifugation or equilibrium density-gradient centrifugation) uses the concept of buoyancy to separate molecules in solution by their differences in density. (wikipedia.org)

Pellets were resuspended in one-twentieth of the original volume with caesium chloride (CsCl) buffer and subjected to isopycnic ultracentrifugation. (nih.gov)
The DNA of Rhynchosciara hollaenderi was examined using isopycnic centrifugation in neutral CsCl. (semanticscholar.org)

The book also ponders on the practical aspects of rate-zonal centrifugation, including gradient materials, density and viscosity of glycerol solutions, and resolution and gradient shape. (elsevier.com)
The publication examines fractionations in zonal rotors and the quantitative aspects of rate-zonal centrifugation. (elsevier.com)
The three main methods of separation are differential pelleting, rate‐zonal centrifugation and isopycnic centrifugation. (els.net)
Particles can be separated on the basis of their size using differential pelleting or rate‐zonal centrifugation. (els.net)
For use in instruments classified: HRS Major Applications: Rate-zonal and isopycnic centrifugation of viruses, rate-zonal centrifugation of RNA. (beckman.com)

In general isopycnic surfaces will occur in fluids in hydrostatic equilibrium coinciding with equipotential surfaces formed by gravity. (wikipedia.org)
6. It was shown that forces greater than 18400g av. for 2h have to be used before chick liver mitochondria reach isopycnic equilibrium. (biochemj.org)

Isopycnic separation can vary significantly depending on the medium used because the density of the biological particles is sensitive to osmotic pressure of the gradient media. (hugecount.com)
Centrifugation is a process that involves the use of the centrifugal force for the separation of mixtures, used in industry and in laboratory settings. (newworldencyclopedia.org)
Centrifugal Separations in Molecular and Cell Biology focuses on the application of modern centrifugation technology in molecular and cell biology, including the separation and fractionation of biological particles by centrifugation on the preparative and analytical scales. (elsevier.com)
Topics include separation by isopycnic banding, large-scale preparative procedures, and density-gradient solutes. (elsevier.com)
The choice of centrifugation method depends on the nature of the particles and often more than one separation technique is required. (els.net)
Many centrifugation purification procedures involve sequential centrifugation steps, often a size separation followed by purification using isopycnic gradient centrifugation. (els.net)
Effect of rotor type on the separation of isotope-labeled and unlabeled Escherichia coli RNA by isopycnic density ultracentrifugation. (semanticscholar.org)
PEG is a polymer of differing length that is usually used to study the structure of a protein or for separation, such as in density gradient centrifugation (isopycnic centrifugation). (madsci.org)
7. The fluid concentrator of claim 1, wherein the separation chamber defines a longitudinal orientation during centrifugation, and wherein the filter housing and filter define a longitudinal flow direction of the extracted fraction during filtration, with the longitudinal flow direction corresponding to the longitudinal orientation of the separation chamber. (freepatentsonline.com)

Isopycnic centrifugation refers to a method wherein a density gradient is either pre-formed or forms during high speed centrifugation. (wikipedia.org)

For example, membrane fractionation often involves first making an enriched fraction from a cell homogenate by differential pelleting followed by isopycnic centrifugation to obtain purified fractions. (els.net)
Flow chart of a typical differential centrifugation of a cell or tissue homogenate. (els.net)
Differential centrifugation of a homogenate: (a) before centrifugation and (b) after centrifugation. (els.net)
After removal of starch and large tissue pieces by filtration, differential centrifugation is used to remove residual starch as well as larger organelles. (bio-protocol.org)

Rate‐zonal or sedimentation velocity density gradient centrifugation. (els.net)
By combining isopycnic and rate zonal sucrose density gradient centrifugation with phase partitioning, we obtained a highly enriched dense vesicle fraction. (plantcell.org)
Whole homogenate of guinea-pig small intestine mucosa was analysed by centrifugation in a zonal rotor. (athabascau.ca)
1. Rate dependent and isopycnic banding in a zonal rotor were used to analyse the subcellular sites of enzymes in homogenates of guinea-pig small intestinal mucosa. (athabascau.ca)

Isopycnic centrifugation through sucrose density gradient provides a method for differentiating normally filled, partially filled, and empty storage vesicles. (aspetjournals.org)

While using isopycnic centrifugation, the particles can never sediment to the bottom of the tube regardless of the time. (hugecount.com)
Upon centrifugation, some particles of specific density sediment until their density is the same as the gradient media. (hugecount.com)
Only then is the gradient said to be isopycnic and can the particles be separated according to their buoyancy. (hugecount.com)
Centrifugation is the use of the centrifugal forces generated in a spinning rotor to separate biological particles, such as cells, viruses, sub‐cellular organelles, macromolecules (principally proteins and nucleic acids) and macromolecular complexes (such as ribonucleoproteins and lipoproteins). (els.net)
The first two methods separate particles primarily on the basis of size while isopycnic centrifugation separates particles on the basis of their density. (els.net)
Depending on the centrifugation force used, particles from cells to those as small as macromolecules can be separated. (els.net)
Alternatively, particles can be separated on the basis of their density using isopycnic centrifugation. (els.net)
b-d) With increasing centrifugation time, the particles in the sample zone move down through the gradient as discrete bands. (els.net)
The term "isopycnic" is also encountered in biophysical chemistry, usually in reference to a process of separating particles, subcellular organelles, or other substances on the basis of their density. (wikipedia.org)
These samples would be pooled and processed by using available technology to isolate virus particles en masse, recover viral nucleic acids, produce amplified shotgun libraries, carry out shotgun sequencing of the mixture of viral genomes, and reconstruct these genomes in silico with the techniques originally developed to sequence the entire human genome from random fragments. (cdc.gov)

Discussions focus on the basic concepts of sedimentation theory, centrifugation methods, designing centrifugation experiments, care of centrifuges and rotors, and statistical estimation of molecular parameters. (elsevier.com)
1. Rate sedimentation and isopycnic centrifugation were used to analyse the subcellular sites of enzymes in homogenates of goldfish intestinal mucosa. (athabascau.ca)

On isopycnic-density-gradient ultracentrifugation one component banded at rho = 1.031 g/ml and the other at rho = 1.054 g/ml. (portlandpress.com)

The lysosomal peak, from which Percoll was removed by centrifugation, was taken as the purified lysosome fraction (L). Lysosomes of fraction L were purified 45-55-fold (as compared with the homogenate) and contained about 5% of the total thyroid acid hydrolase activities. (portlandpress.com)
In conclusion, a 50-fold purification of pig thyroid lysosomes was achieved by using a new tissue-disruption procedure and isopycnic centrifugation on Percoll gradient. (portlandpress.com)
Parasite synchronization was performed by culturing late-stage schizont parasites for a defined period of time, subjecting them to Percoll density centrifugations, and collecting the newly formed rings. (biomedcentral.com)
By taking advantage of Plasmodium 's periodic lifecycle in erythrocytes, it is shown that Percoll density centrifugation alone is sufficient to tightly synchronize cultures with minimal parasite loss. (biomedcentral.com)
One of the most common procedures used to obtain synchronized cultures is Percoll density centrifugation. (biomedcentral.com)
The original isopycnic Percoll method, established in 1981 for Plasmodium berghei [ 5 ] and 1983 for Plasmodium falciparum [ 6 ], was unable to tightly synchronize parasite stages because it could not separate late trophozoites and early schizonts from late schizonts. (biomedcentral.com)
the isolation of matured parasites by centrifugation on Percoll cushions, and sorbitol treatment of schizont stages. (biomedcentral.com)

Transmembrane mucins were purified from stratified corneal epithelial cell cultures using size exclusion chromatography and isopycnic density centrifugation. (arvojournals.org)
Radiolabeled proteoglycans from the culture medium and the cell layer were isolated and separated by isopycnic density-gradient centrifugation, followed by gel, ion-exchange and hydrophobic-interaction chromatography. (lu.se)

Isopycnic centrifugation in cesium trifluoroacetate yielded RNA with the lowest possible amounts of contaminating DNA. (nih.gov)

6. The method of claim 1 , wherein the harvested cells are separated by density centrifugation. (google.com)

RNA was extracted from root material and rhizosphere soil and subjected to cesium gradient centrifugation followed by 16S rRNA amplicon pyrosequencing to identify microorganisms enriched with 13 C. Thirty operational taxonomic units (OTUs) were labeled and mostly corresponded to Proteobacteria (13 OTUs) and Verrucomicrobia (8 OTUs). (asm.org)

The equipment used for centrifugation is called a centrifuge , and the vessel that spins the samples is called a rotor . (newworldencyclopedia.org)

The sample is usually mixed with a solution of known gradient materials and subjected to centrifugation. (bioportfolio.com)

Isopycnic centrifugation showed that CA125, CAMOv2 and CAMOv8 carrying molecules had the same high densityy (1.46 g/ml) in the first peak, whereas CA125 molecules had a lower density (1.41 g/ml) in the second peak. (elsevier.com)

The selection first covers the principles and practices of centrifugation and the bases of centrifugal separations. (elsevier.com)

Protocols for centrifugation typically specify the amount of acceleration to be applied to the sample, rather than specifying a rotational speed such as revolutions per minute. (newworldencyclopedia.org)
Isopycnic typically describes surfaces, not processes. (wikipedia.org)

1. Two populations of morphologically intact mitochondria were isolated from embryonic, neonatal and adult chick liver by isopycnic centrifugation. (biochemj.org)

An isopycnic surface is a surface of constant density inside a fluid. (wikipedia.org)
The term "isopycnic" is commonly encountered in the fluid dynamics of compressible fluids, such as in meteorology and geophysical fluid dynamics, astrophysics, or the fluid dynamics of explosions or high Mach number flows. (wikipedia.org)

These formations are, relative to other lithospheric formations, cooler and less dense but much more isopycnic. (wikipedia.org)

The guanine-plus-cytosine (G+C) ratio of the deoxyribonucleic acid (DNA) was determined for 7 Acholeplasma and 24 Mycoplasma species by a new method that combines a micro-scale preparation of DNA with isopycnic gradient centrifugation. (microbiologyresearch.org)

In chemistry and biology , centrifugation increases the effective gravitational force on a mixture in a test tube, to rapidly and completely bring the precipitate ("pellet") to the bottom of the tube. (newworldencyclopedia.org)

Isopycnic sucrose density gradient centrifugation showed that the lipoprotein complexes isolated in the membrane fraction covered a broad density range, but, in general, were higher in density than SMM lipoproteins and lower in density than the high density fraction of MFGM material. (diaa.asn.au)

The technique used to measure excision repair involved isopycnic centrifugation of density- and isotopically-labeled DNA. (nih.gov)

Unless there is a flux of mass into or out of a control volume, a process which occurs at a constant density also occurs at a constant volume and is called an isochoric process and not an isopycnic process. (wikipedia.org)