Paper-electrophoresis

Electrophoresis is for separating ions, since only ions will migrate under the influence of an electric field, negative ions to the positive electrode and positive ions to the negative electrode. Scientists have found electrophoresis especially useful in biochemistry experiments in which charged amino acid molecules and other biomolecules need to be separated. Thus, application to protein and nucleic acid analysis has been popular (see Chapter 16). 

Gel cast between glass plates. Notches are cast in the top of the gel to receive samples. 

Paper electrophoresis represents one of the most early developed electromigration techniques. The first references go back to 1950 [1-6]. The flourishing era of paper electrophoresis has already passed the main reason being a shift to other more 

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Paperboard materials PAPERCHEM Paper chromatography Pap er-co a ting pigmen t Paper colorants Paper coloring Paper electrophoresis Paper fiber Paper formation aids Paper grades Paper industry... 

Paper Electrophoresis. Paper (qv) as an electrophoretic matrix was employed in some of the first electrophoretic techniques developed to separate compounds. Paper is easier than a gel matrix because the paper matrix requires no preparation. Besides being easy to obtain, paper is a good medium because it does not contain many of the charges that interfere with the separation of different compounds. Two types of paper employed in this type of electrophoresis are Whatman 3 MM (0.3 mm) and Whatman No. 1 (0.17 mm). 

The difference between paper electrophoresis and paper chromatography is that electrophoresis separates by charge whereas chromatography... 

Some advantages of paper in electrophoresis are that paper is readily available, easy to handle, and new methodologies can be developed rapidly. The disadvantages of paper electrophoresis are that the porosity of paper caimot be controlled, the technique is not very sensitive, and it is not easily reproducible. 

HCl aq EtOH). Recrystd from warm, acidified EtOH by addition of ammonia. The crude material (Ig) can be extracted with EtOH (50mL) in a Soxhlet apparatus for lOh to remove impurities. Impurities can be detected by paper electrophoresis. [Petrova et al. Anal Lett 5 695 1972.]... 

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. 

Peschanski, using the isotopic method ( ° Hg), has found complete exchange (0 °C) in methanol and various other non-aqueous media. The separation methods used were, (a) paper and column chromatography, (b) paper electrophoresis, and (c) precipitation of Hg(I) with chloride. In the presence of cyanide ions, however, less than complete exchange could be observed. Zero-time exchange was again found to vary in the same manner as for aqueous media. Similar effects were observed in the presence of chloride ions. 

There are a few other analytical methods in which electrochemistry plays an essential role, such as (paper) electrophoresis, isotachophoresis, electrography and electrochromatography (according to Fujinaga) as they belong to analytical separation techniques, they are beyond the scope of this book. 

The paper electrophoresis experiments carried out to study the mobility of polynuclear technetium clusters in aqueous solutions of HX of varying acidity, as a mobile phase, showed that these clusters were also characterized by reversible reactions such as (5) without leading to destruction of M-M bonds. On the other hand, an autoclave recrystallization of the polynuclear clusters at 200-220°C in an atmosphere of argon from concentrated solutions of HX led to a partial destruction of M-M bonds and the formation of binuclear complexes [Tc2X8]3 and [Tc,X6]2. This indirectly shows that reactions (6) and (7), leading to the destruction of M-M bonds, are likely in solutions of polynuclear clusters [15]. 

Solution equilibria of Fe(III)/Cr(III) in methionine and Fe(III)/Cr(III) in methio-nine/penicillamine complex systems were studied by paper electrophoresis and were reported by Tewari [38]. The formation of 1 1 1 mixed ligand complexes is inferred, and the stability constants of the complexes at 35 °C and 0.1 M ionic strength were 6.80 0.09 (Fe(III) methionine penicillamine) and 4.60 0.16 (Cr(III)-methionine-penicillamine), respectively. 

Perham, R.N., and Jones, G.M.T. (1967) The determination of the order of lysine-containing tryptic peptides of proteins by diagonal paper electrophoresis. Eur. J. Biochem. 2, 84-89. 

Aspirin can be separated from salicylic acid by ionophoresis at a pH of 4-5.1 8 Separation of aspirin in combination products has been achieved with paper strip electrophoresis, using buffers at pH 2-8 and a 200 V. applied potential.11 9 Aspirin was separated from metabolites by paper electrophoresis in a phthalate buffer of pH 3.2 and an ionic strength of 0.0125-0.0500.150... 

Carr et al- -° have reported the quantitative determination of neomycin in the presence of polymixin and bacitracin. Using paper electrophoresis quantitation of neomycin was accomplished colori-metrically with ninhydrin. 

Budtz-Olsen (B13) has shown that Hp grouping is possible on vertical paper electrophoresis if Consden and Powell s (C3) borate-barbiturate buffer is used, since differences between the migration rate of the different Hp s is then great enough. It is, however, doubtful whether this is possible when the concentration of the Hp is low. 

Malabsorption Syndrome, with Special Reference to the Effects of Wheat Gluten (Frazer), 5, 69 Mellituria, Nonglucose (Sidbury), 4, 29 Microbiological Assay Methods for Vitamins (Baker and Sobotka), 5, 173 Organic Acids in Blood and Urine (Nordmann and Nordmann), 4, 53 Paper Electrophoresis Principles and Techniques (Peeters), 2, 1 Paper Electrophoresis of Proteins and Protein-Bound Substances in Clinical Investigations (Owen), I, 238 Parathyroid Function and Hyperparathyroidism, Biochemical Aspects of (Nordin), 4, 275... 

PVA as, 25 618-619 silica in, 22 376-377 titanium dioxide in, 25 27-28 VDC lacquer resins for, 25 735 Paper coloring, 9 222-224 Paper electrophoresis, 9 750-751 Paper fibers... 

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