Sample Migration

capillary filled with electrolyte causes a bulk EOF of solution along the capillary.[2] This results from a characteristic of fused silica capillaries in which the inner wall becomes covered with acidic silanol groups. The degree of EOF is dependent on the pH. At a pH below 4, the ionization is small, and so the EOF flow rate is not significant. Silanol groups become fully ionized at pH>9, which produces a strong EOF. To maintain electrical neutrality, cations build near the surface. Under the influence of an applied voltage, these cations, and the water molecules dissolving them, migrate toward the cathode, resulting in a net solution flow along the capillary. At pH of 7 or more, the EOF is strong enough to sweep anions to the cathode regardless of their charge, thereby allowing separation and analysis of analytes with mixtures of size and charge.[2]

If EOF is undesirable for analysis, it can be reduced or eliminated by coating the internal surface of the capillary or adding surfactants and/or buffer additives to the separation buffer.[4] Reducing or eliminating the EOF leads to a more efficient and reproducible separation of DNA fragments. Without the effect of EOF, the order in which DNA fragments migrate in gels with CGE is dependent on their molecular size, with smaller fragments having a shorter migration time (like slab gel electrophoresis).1-3-1

The mobility of sample ions under the influence of applied voltage is dependent on their charge/mass ratio. Therefore, when separating a sample, smaller, more highly charged ions will be detected first, followed by larger, lesser-charged ions. Application of voltage across a

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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