Gel Zone Electrophoresis

Another alternative technique commonly used to investigate the electrophoretic properties of a material (especially soluble macromolecules) or mixtures thereof is gel or zone electrophoresis. The technique involves the use of a 

Gel electrophoresis requires very small sample sizes and can, in theory at least, give complete separation of a mixture of substances. While it cannot be used to determine electrophoretic mobilities, it allows for the separation and identification of components that would be extremely difficult or impossible to separate using other techniques. It is especially applicable to biological systems where sample availability may be a problem. It may even be used as a small-scale preparative procedure. 

Since the other electrokinetic phenomena are of significantly lesser practical importance, they will not be discussed here. For further theoretical and experimental details, the reader is referred to the works cited in the Bibliography. 

Although often slighted or completely ignored, the nature of the electrical double layer can have an important influence in the characteristics and function of practical colloidal systems. The potential, for example is a number characterizing the EDL that is often suspect because of doubts related to the technique used in its determination. Even approximate numbers, however, can be useful in practice since they may help avoid situations that would obviously be detrimental to the proper functioning of the system, if known and understood. Some practical examples of the importance of information about surface charge and potential include the following areas. 

In mineral foam or froth flotation the sign and magnitude of the surface charge will influence the adsorption of additives (collectors) onto the mineral surface that will determine whether a specific mineral will float or sink, and therefore the efficiency of ifs separafion. The process of flofafion is based on fhe interacfions af fhe solid-liquid and solid-liquid-air inferfaces. The addi-fion of fhe proper collecfor defermines whaf mineral fraction will become 

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Eisinger (1971) and Eisinger and Blumberg (1972) have developed the theory of gel zone electrophoresis of species in rapid association-dissociation equilibrium. It is clear that in a monomer-dimer self-... 

The use of standards with samples makes zone electrophoresis particulady usehil as an analytical tool. However, when samples caimot be analyzed on the same gel, differences in the experimental conditions from experiment to experiment make direct comparison more difficult. To make comparisons from experiment to experiment, a relative mobility, is often measured by measuring the distance a component travels down the gel compared to some reference or standard component. 

Disc Electrophoresis. Resolution in zone electrophoresis depends critically on getting sample components to migrate in a focused band, thus some techniques ate employed to concentrate the sample as it migrates through the gel. The most common technique is referred to as discontinuous pH or disc electrophoresis. Disc electrophoresis employs a two-gel system, where the properties of the two gels are different. 

Electrodriven Separation Techniques encompass a wide range of analytical procedures based on several distinct physical and chemical principles, usually acting together to perform the requh ed separation. Example of electrophoretic-based techniques includes capillary zone electrophoresis (CZE), capillary isotachophoresis (CITP), and capillary gel electrophoresis (CGE) (45-47). Some other electrodriven separation techniques are based not only on electrophoretic principles but rather on chromatographic principles as well. Examples of the latter are micellar... 

Butterman, M Tietz, D Orban, L Chrambach, A, Ferguson Plots Based on Absolute Mobilities in Polyarcylamide Gel Electrophoresis Dependence of Linearity of Polymerization Conditions and Application on the Determination of Free Mobility, Electrophoresis 9, 293, 1988. Caglio, S Chiari, M Righetti, PG, Gel Polymerization in Detergents Conversion Efficiency of Methylene Blue vs. Persulfate Catalysis, as Investigated by Capillary Zone Electrophoresis, Electrophoresis 15, 209, 1994. 

Cagho, S Righetti, PG, On the Efficiency of Methylene Blue versus Persulfate Catalysis of Polyacrylamide Gels, as Investigated by Capillary Zone Electrophoresis, Electrophoresis 14, 997, 1993. 

Raymond, S Weintranb, LS, Acrylamide Gel as a Supporting Medium for Zone Electrophoresis, Science 130, 7111,1959. 

Weiss, GH Garner, M Yarmola, E Bocek, P Chrambach, A, A Comparison of Resolution of DNA Fragments Between Agarose Gel and Capillary Zone Electrophoresis in Agarose Solutions, Electrophoresis 16, 1345, 1995. 

CE was recently used for anthocyanin analysis because of its excellent resolution. This technique has different modes capillary zone electrophoresis (CZE), capillary gel electrophoresis (CGE), micellar electrokinetic chromatography (MEKC), capillary electrochromatography (CEC), capillary isoelectric focusing (CIEE), and capillary isotachophoresis (CITP)."° CZE is the most popular method for anthocyanin... 

Sweedler reported a two-dimensional separation, where fluorescein thiocarbamyl derivatives of peptides were separated by capillary zone electrophoresis in the first dimension (Liu and Sweedler, 1996). The outlet of the capillary was wiped across the top of an SDS-PAGE gel, where peptides were then separated based on their size. 

Widhalm, A., Schwer, C., Blaas, D., Kenndler, E. (1991). Capillary zone electrophoresis with a linear, non-cross-linked polyacrylamide gel separation of proteins according to molecular mass. J. Chromatogr. 549, 446 451. 

The pectinesterase produced by Sclerotinia libertiana78 was purified on columns of Duolite A-2, Amberlite CG-50, and CM-cellulose. The final product was purified 266-fold, its sedimentation coefficient was calculated to be 4.41 S, and zone electrophoresis in starch gel showed a slight contamination of this product. 

Traditional electrophoresis involves the differential migration of charged species in an electrolyte solution under the influence of an applied potential gradient. The rate of migration of each species is a function of its charge, shape and size. In traditional zone electrophoresis, the electrolyte solution is retained by an inert porous supporting medium, usually paper or gel, in the form of a sheet or column. Application of a dc potential across the solution for a period of time results in the components of a mixture, originally placed... 

Several modes of capillary electrophoretic separation are available ordinary CE, capillary zone electrophoresis, capillary electrokinetic chromatography, capillary gel electrophoresis, capillary electrochromatography, capillary isota-chophoresis, and capillary isoelectric focusing. The different separation mechanisms make it possible to separate a wide variety of substances depending on their mass, charge, and chemical nature.53... 

DGE a AC AMS APCI API AP-MALDI APPI ASAP BIRD c CAD CE CF CF-FAB Cl CID cw CZE Da DAPCI DART DC DE DESI DIOS DTIMS EC ECD El ELDI EM ESI ETD eV f FAB FAIMS FD FI FT FTICR two-dimensional gel electrophoresis atto, 10 18 alternating current accelerator mass spectrometry atmospheric pressure chemical ionization atmospheric pressure ionization atmospheric pressure matrix-assisted laser desorption/ionization atmospheric pressure photoionization atmospheric-pressure solids analysis probe blackbody infrared radiative dissociation centi, 10-2 collision-activated dissociation capillary electrophoresis continuous flow continuous flow fast atom bombardment chemical ionization collision-induced dissociation continuous wave capillary zone electrophoresis dalton desorption atmospheric pressure chemical ionization direct analysis in real time direct current delayed extraction desorption electrospray ionization desorption/ionization on silicon drift tube ion mobility spectrometry electrochromatography electron capture dissociation electron ionization electrospray-assisted laser desorption/ionization electron multiplier electrospray ionization electron transfer dissociation electron volt femto, 1CT15 fast atom bombardment field asymmetric waveform ion mobility spectrometry field desorption field ionization Fourier transform Fourier transform ion cyclotron resonance... 

Smithies, O., Zone electrophoresis in starch gels group variations in the serum proteins of normal human adults. Biochem. J. 61, 629 (1955). 

Another separation technique utilizes an electric field. An electric held is an electrically charged region of space, such as between a pair of electrodes connected to a power supply. The technique utilizes the varied rates and direction with which different organic ions (or large molecules with charged sites) migrate while under the influence of the electric held. This technique is called electrophoresis. Zone electrophoresis refers to the common case in which a medium such as cellulose or gel is used to contain the solution. A schematic diagram of the electrophoresis apparatus resembles an electrochemical apparatus in many... 

Describe the following electrophoresis, zone electrophoresis, paper electrophoresis, gel electrophoresis, isoelectric focusing, and capillary electrophoresis. 

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