Molar mass electrophoresis

Bravo, 1984). Hybrids of these systems, where chromatography and electrophoresis are used in each spatial dimension, were reported nearly 40 years ago (Efron, 1959). Belenkii and coworkers reported on the analysis of block copolymers by TLC (Gankina et al., 1991 Litvinova et al., 1991). Two-block copolymers of styrene and f-butyl methacrylate were separated first with regard to chemical composition by TLC at critical conditions, followed by a SEC-type separation to determine the molar masses of the components. 

Protein molar mass standards covalently labeled with dyes are valuable when the electrophoresis is followed by a Western blot or when electrophoresis has to be monitored. Furthermore, procedures of gel staining alter the geometry, and assignment of bands on blot to marker bands within the gel is sometimes difficult. 

Fill the gel particles together with the surrounding buffer into the tube. The tube is inserted into the vertical electrophoresis apparatus (dialysis membrane down to anode), electrode buffer is poured, and electroelution is started with 10 mA per tube for 3-8 h, depending on tbe molar mass of the protein. 

Thus, electrophoresis commonly measures size/charge ratios of migrating molecules (or, better, charge/size ratios (z/dft). The Stokes diameter of a protein [nm] is related to the molar mass Mr [g moh1] by Eq. (9.17). 

In biochemistry gel electrophoresis is the method of choice for the separation of various kinds of macromolecules (e.g. nucleic acids, proteins). It is also used in dendrimer chemistry for separation and as a method of determining relative molar masses and for qualitative assessment of the purity of a dendrimer sample. 

Molar mass versus generation low-angle laser light scattering (LALLS) chemical ionization, fast atom bombardment, laser desorption and electrospray mass spectroscopy vapor phase osmometry electrophoresis. 

The electrophoresis technique most often used with proteins is SDS-PAGE, i.e., polyacrylamide gel electrophoresis carried out in the presence of 0.1 % sodium do-decyl sulphate (See and Jackowski 1989). This technique, which was developed by Shapiro, Vinuela and Maizels, separates proteins, or more accurately protein subunits, exclusively on the basis of their molar mass. SDS is an anionic detergent that binds to proteins up to a level of about 1.4 g g 1 of protein, and in so doing it disrupts the quaternary, tertiary and, to a large extent, the secondary structure of the... 

Electrophoresis is without doubt the most convenient and accurate method for determining the size of nucleic acids (Sect. 4.2). For double stranded nucleic acids, electrophoresis is carried out under non-denaturing conditions using a polyacrylamide or agarose matrix, depending on the size of the nucleic acid. For single stranded nucleic adds, electrophoresis should be conducted in the presence of urea, to disrupt any partially based-paired structures that may influence mobility. In both cases, the samples of interest should be run together with molar mass standards, which can either be prepared in the laboratory or purchased. 

Along with the gel electrophoresis, capillary electrophoresis (CE) was successfully applied for the separation of HA fragments. CE is a high-resolution, rapid, quantitative method suitable for low molar mass HA samples. Procedures for the fractionation and the characterization of HA oligomers are well established and described in detail [269,270]. 

Vreeland, W. N. et al. Molar mass profiling of synthetic polymers by free-solution capillary electrophoresis of DNA-polymer conjugates. AnaZyficaZ Chemistry 13, 1795-1803 (2001). 

NMR, FTIR, XPS, aqueous electrophoresis, DLS, and TEM. The livingness of the process was, however, only indirectly shown by the increased amount of grafted polymer with the increase in targeted molar mass. 

The movement of an electrically charged particle of mass m and charge Q under the influence of a uniform electric field of strength E is called electrophoresis. These particles may be biological cells, colloids, macromolecules, or low-molar-mass substances. Even electrically neutral particles can be made electrophoretically mobile through formation of suitable complexes. An example is the formation of borate complexes by polysaccharides ... 

An important application of the preceding material is to the determination of the molar mass of biological macromolecules. Electrophoresis is the motion of a charged species, such as DNA and ionic forms of amino acids, in response to an electric field. Electrophoretic mobihty is a result of a constant drift speed, so the mobility of a macromolecule in an electric field depends on its net charge, size (and hence molar mass), and shape. 

Fig. 8.18 The experimental steps taken during separation of a mixture of biopolymers by two-dimensional electrophoresis, (a) Isoelectric focusing is performed on a thin gel slab, resulting in separation along the vertical direction of the illustration, (b) The first slab is attached to a second, larger slab and SDS-PAGE is performed with the electric field oriented in the horizontal direction of the illustration, resulting in further separation by molar mass. The dashed horizontal lines show how the bands in the two-dimensional gel correspond to the bands in the gel on which isoelectric focusing was performed.

Other mass spectral techniques that use LC and capillary electrophoresis (CE) as the sample introduction method make it possible to analyze chemicals that should otherwise be derivatized for GC analysis, and also those nonvolatile and nonderiva-tizable chemicals that cannot be analyzed at all with GC. Many of these chemicals could be analyzed with FUR without GC separation, but in the environment, they may be in, for example, water or soil samples (which possibly have to be extracted with water). Water samples are difficult to analyze with FTIR since water is quite a poor solvent for FTIR due to very high molar absorptivity. 

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