Electrophoretic field

Factor migrates in an electrophoretic field between a- and (3-globulins, a-(3-Globulin. 

M.J. Heller, A.H. Forster, and E. Tu, Active microelectronic chip devices which utilize controlled electrophoretic fields for multiplex DNA hybridization and other genomic applications. Electrophoresis 21, 157-164 (2000). 

Particles must possess a net charge to migrate in a electrophoretic field. All the dendrimers that have been analyzed using gel electrophoresis have either cationic or anionic groups that may be ionized at appropriate pH values and form charged particles. 

The lactate and acetate ions have one unit of charge and the respective electrophoretic mobilities of 13.1 x 10 5 and 16.6 x 10 5 cm2/V s in 0.1 M alkaline solution at 20°C. How far through such a solution must they travel before unit resolution is achieved using an electrophoretic field strength of 20 V/cm How long does it take and how many theoretical plates are needed Assume ideal electrophoresis (0 = 1). 

Carle, G., Frank, M., Olson, M. (1986) Electrophoretic separations of large molecules by periodic inversion of the electrophoretic field, Science 232, 65-68. 

Photometric detectors are the most popular in CE instruments including diode array detectors. Laser-induced fluorescence (LIE) detection and electric conductivity detectors are also popular. LIE is particularly sensitive and powerful for detecting low concentration analytes. However, most analytes are not natively fluorescent and some derivatizations are necessary. Conductivity detector is useful for the detection of non-ultraviolet (non-UV) absorbing analytes such as inorganic ions or fatty acids. Both LIE detection and conductivity detectors are commercially available and easy to interface with conventional CE instruments. Electrochemical detectors are also useful for selective high-sensitivity detection. Several techniques have been developed to circumvent the problem of strong effects of electrophoretic field on electrochemical detection, but despite this, commercial electrochemical detectors are not used extensively. 

Figure 3 Examples of polyplex characterization via gel electrophoresis and TEM. (a) Gel electrophoresis shift assay of a polymer bound to pDNA at the N/P ratios indicated. N/P = 0 indicates pDNA only, which migrates with the electrophoretic field. At N/P = 2, the polymer binds pDNA and prevents its migration with the electrophoretic field, (b) TEM of poly-plexes. Adapted from Liu, Y. Wenning, L. Lynch, M. Reineke, T. M. J. Am. Chem. Soc. 2004, 126, 7422. ...

During electrotransfer, an electrophoretic field is generated to transfer proteins from a polyacrylamide matrix to a membrane matrix (also known as Western blotting). Two types of system are used for electrotransfer ... 

The theory of conductivity has been improved by eliminating some of the assumptions implicit in its derivation.The coupling of the relaxation field and the electrophoretic field has been accounted for. The effect of finite ion size and of ion-pair formation has also been taken into consideration. 

The first effect arises because the ion atmosphere is greatly modified at high fields. The ion velocity is very large and the ion traverses distances comparable to that of the radius of the ion atmosphere in times so short that the atmosphere cannot reform. As a consequence the relaxation field is destroyed and the electrophoretic field significantly altered. There is less retardation X increases, approaching a high field limit. 

P synthetase from patient T.B. migrates faster in an electrophoretic field at pH 8.6 than does the enzyme from normal individuals indicating structural alteration in the mutant enzyme (Figure 3). 

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