Nonequilibrium capillary electrophoresis

Berezovski, M. and A. Drabovich, et al. (2005). Nonequilibrium capillary electrophoresis of equilibrium mixtures a universal tool for development of aptamers. J Am Chem Soc 127, 3165-3171... 

Whereas oligonucleotide libraries were traditionally partitioned by filtration or capture on beads or on affinity columns, capillary electrophoresis has been validated as a promising alternative. Aptamers displaying a high affinity were obtained in a very limited number of selection rounds. Nonequilibrium capillary electrophoresis of equilibrium mixtures led to the identification of DNA aptamers... 

Two methods have been used so far for aptamer-related applications nonequilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) and equilibrium capillary electrophoresis of equilibrium mixtures (ECEEM). An equilibrium mixture is defined as a mixture of the target and the ligand (or a mixture of ligands) which is incubated until equilibrium is reached in reaction (9.1), so that the concentrations of molecules and complexes are related as [L][T]/[L T] = K. ... 

Berezovski, M., Krylov, S. N. (2004). Using nonequilibrium capillary electrophoresis of equilibrium mixtures for the determination of temperature in capillary electrophoresis. Anal Chem 76, 7114-7117. 

Every set of qualitatively unique initial and boundary conditions for system 11.3 defines a unique KCE method. Here we will describe six KCE methods nonequilibrium capillary electrophoresis of the equilibrium mixtures (NECEEM), sweeping CE (SweepCE), eontinuous NECEEM (cNECEEM), short SweepCE (sSweepCE), plug-plug KCE (ppKCE), and short SweepCE of Equilibrium Mixture (sSweepCEEM). Table 11.1 contains drawings that schematically illustrate initial and boundary conditions and show the mathematical representation of initial and boundary conditions. It also contains representative functions L(t), T t), and C t) for a fixed x for each method. The notion of equilibrium mixture (EM) refers to the mixture of L, T, and C at equilibrium, typically prepared... 

Nonequilibrium capillary electrophoresis of the equilibrium mixtures (NECEEM) is a unique KCE method that facilitates finding both and off from a single electropherogram. Mechanistically, it is similar to previously introduced affinity probe capillary electrophoresis (APCE) ° and falls... 

Okhonin, V., Krylova, S.M., and Krylov, S.N., Nonequilibrium capillary electrophoresis of equilibrium mixtures, mathematical model, Anal. Chem., 76, 1507, 2004. 

Okhonin, V. Krylova, SM. Krylov, SJM. Nonequilibrium capillary electrophoresis of equilibrium mixtures, mathematical model. Anal. Chem. 2004, 76 (5), 1507-1512. Mellors, J.S. Gorbounov, V. Ramsey, R.S. Ramsey, J.M. Fully integrated glass microfluidic device for performing high-efficiency capillary electrophoresis and electrospray ionization mass spectrometry. Anal. Chem. 2008, 80 (18), 6881-6887. 

Sloat AL, Roper MG, Lin X, Ferrance JP, Landers JP, Colyer CL (2008) Protein determination by microchip capillary electrophoresis using an asymmetric squarylium dye noncovalent labeling and nonequilibrium measurement of association constants. Electrophoresis 29 3446-3455... 

Aptamers, based on either RNA or DNA sequences, offer a potential replacement or adjunct to antibody-based detection of ricin (Proske et al., 2005). Both DNA- and RNA-based aptamers bind ricin and can approach the specificity of an antibody-antigen interaction (Hesselberth et al., 2000 Tang et al., 2006). Ricin has been detected at levels of approximately 14 ng/mL using fluorescently labeled RNA-based aptamers and capillary electrophoresis under nonequilibrium conditions (Haes et al., 2006). 

The experiments were run in a continuous-flow stirred tank reactor (CSTR) (fig. 6.2) with the reaction system at a nonequilibrium stationary state, such that the reactions run spontaneously from glucose to G3P and 3PG. The concentrations of the species at this state are close to those of physiological conditions. The metabolites G6P, F6P, F1,6BP, DHAP, G3P, and 3PG were detected and analyzed by capillary electrophoresis. Typical relative errors were 4% for G6P, 11% for F6P, 15% for F1,6BP, 9% for DHAP, 6% for 3PG and 3% for G3P. 

Capillary nonequilibrium pH gradient gel electrophoresis in conjunction with mini slab polyacrylamide electrophoresis is a rapid, cost-effective, and easy-to-handle system for the two-dimensional analysis of complex protein mixtures in one day. 

---