Electrophoresis carrier

In the case of carrier electrophoresis, a sheet of paper, starch, polyacrylamide or agarose gel or similar materials, where the respective solid phase is saturated with buffer solution, are placed between the electrodes in order to generate a homogeneous, rectified electrical field. The mixture of substances to be separated is supplied as a single spot and the individual components are then separated in the course of time. Carrier electrophoresis is therefore a discontinuous separation process. 

The particles move in a solvent, typically aqueous salt solutions, in free electrophoresis or Tiselius electrophoresis. In carrier electrophoresis, the particles move in a swollen carrier [for example, paper, starch gels, cross-linked poly(acrylamide)]. 

Carrageen, Carrageenan carriage Schlitten carrier Trager (auch chromat), Schleppmittel (Gas/Fltlssigkeit) carrier electrophoresis Tragerelektrophorese, Elektropherografie carrier gas (an inert gas)... 

Ionic interactions are also used to associate genetic material with nanoparticulate carriers. Electrophoresis is perhaps the easiest way to assess the association efficiency of nucleic acids to a nanostructure. The associated genetic material will not migrate in an electrophoresis gel as would happen with free nucleic acids. It is also useful to visually determine the conformation of the plasmid DNA, supercoiled being the most effective form in comparison to circular and open forms. The association efficiency can be quantitatively determined using commercial kits and fluorescence techniques or, directly but with a lower sensitivity, by UV determination. For this purpose, the free nucleic acid needs to have been previously separated and subsequently quantified. 

In continuous-flow zone electrophoresis the solute mixture to be separated is injec ted continuously as a narrow source within a body of carrier fluid flowing between two electrodes. As the solute mixture passes through the transverse field, individual components migrate sideways to produce zones which can then be taken off separately downstream as purified fractions. 

The thiazolecarboxylic acid structure (40) was also guessed in a similar way, from tracer experiments. The unknown compound was converted into the thiamine thiazole by heating at 100°C and pH 2. On paper electrophoresis, it migrated as an anion at pH 4. Tracer experiments indicated that it incorporated C-l and C-2 of L-tyrosine, and the sulfur of sulfate. The synthetic acid was prepared by carboxylation of the lithium derivative of the thiamine thiazole, and the derivatives shown in Scheme 19 were obtained by conventional methods. Again, the radioactivity of the unknown, labeled with 35S could not be separated from structure 40, added as carrier, and the molar radioactivity remained constant through several recrystallizations and the derivatizations of Scheme 17. 

Because of the instability of many of the compounds involved, it is necessary to determine the chemical recoveries in all cases. This requires the use of macro quantities (10 mg up to several hundred mg) of carriers and target compounds. This, in turn, makes it impractical to use the various thin-layer methods, such as paper and thin-layer chromatography and paper electrophoresis, although such methods have proved useful in identifying products and in checking the purity of fractions. The separation methods now most commonly used are column chromatography and sublimation. 

Shimao, K, Mathematical Simulation of Steady State Isoelectric Eocusing of Proteins using Carrier Ampholytes, Electrophoresis 8, 14, 1987. 

Hjerten, S., Elenbring, K., Kilar, F., Liao, J.-L, Chen, A. J. C., Siebert, C. J., and Zhu, M.-D., Carrier-free zone electrophoresis, displacement electrophoresis and isoelectric focusing in a high-performance electrophoresis apparatus, /. Chromatogr., 403, 47, 1987. 

Bachmartn, K., Boden, J., and Haumann, I., Indirect fluorimetric detection of alkali and alkaline earth metal ions in capillary zone electrophoresis with cerium (III) as carrier electrolyte, /. Chromatogr., 626, 259, 1992. 

Seidel A, Wiener M, Kruger E, et al. 1986. Studies on the lysosomal binding of 141Ce, 239Np, 239Pu and 241 Am in rat and Syrian hamster liver using carrier-free electrophoresis. Int J Rad Appl Instrum B13(5) 515-518. 

Rabilloud, T., Valette, C., and Lawrence, J. J. (1994). Two-dimensional electrophoresis of basic proteins with equilibrium isoelectric focusing in carrier ampholyte-pH gradients. Electrophoresis 15, 1552-1558. 

Carriers can also, in theory, be isolated from the membrane and quantified using gel electrophoresis (or similar techniques), although in practice, it is only possible to measure a protein content and not a carrier number (e.g. [196]). Note that in all of the cases mentioned above, carrier numbers are generally quantified by assuming a 1 1 stoichiometry with a labelled solute. 

Hilder, E. R, Klampfl, C. W., Buchberger, W., and Haddad, P. R. (2002). Comparison of aqueous and nonaqueous carrier electrolytes for the separation of penicillin V and related substances by capillary electrophoresis with UV and mass spectrometric detection. Electrophoresis 23, 414—420. 

---