Indicators, electrophoretic

Fig. 6. Reversal of charge of 0.09% Na arabinate sol by Pb(NOa)2 determined with the aid of five electrophoretic indicators (see curve ""Arab ), together with the reversal of charge of each of these indicators in the absence of Na arabinate.

Fig. 6 gives an example, from which may be concluded that with the sol concentration chosen, the five different kinds of "particles used as "electrophoretic indicators are covered with a complete colloid film. To avoid misinterpretation we must add that the adjective "complete does not give any information on the structure of the colloid film formed. Thus complete does not mean, for instance that a monomolecular colloid film on the particle surface would have been completed. It only means that the mono- di- or perhaps poly-molecular colloid film formed possesses such a boundary with the surrounding sol, that its electrophoretic properties have become independent of those of the original particle surface. 

The electrophoretic velocities of each of the sols separately and of the clear mixture at a ratio of 83.3% gum arabic sol were measured with suspended carborundum particles, these latter serving in the same way as SiOa particles as an electrophoretic indicator The figure shows clearly the interaction of the positive and negative colloid, the electrophoretic velocity being intermediate between those of the gelatin and of the gum arabic, which leads necessarely to the occurrence of a reversal of charge point. Especially we lay stress on the fact, that the electrical interaction is not limited to the actual occurrence of coacervation, for also in those ranges of ratio in which no coacervation occurs (dotted parts of the curve) the electrophoretic velocity decreases on addition of the second colloid. 

Surface active electrolytes produce charged micelles whose effective charge can be measured by electrophoretic mobility [117,156]. The net charge is lower than the degree of aggregation, however, since some of the counterions remain associated with the micelle, presumably as part of a Stem layer (see Section V-3) [157]. Combination of self-diffusion with electrophoretic mobility measurements indicates that a typical micelle of a univalent surfactant contains about 1(X) monomer units and carries a net charge of 50-70. Additional colloidal characterization techniques are applicable to micelles such as ultrafiltration [158]. 

Under certain conditions the sample is clearly visible throughout the process. Other times it is necessary to stain the matrix to visualize the components. In cases where a final staining procedure is required, a small amount of dye is often added to the sample before the analysis. The dye typically migrates faster than any sample component. The position of the dye in the matrix indicates the speed of the resolution of the components of the sample. Typically, the electrophoretic medium is discarded after use. Good resolution can be obtained from 1 to 20 hours, using applied voltages of 10 to 2000 V and currents of 5 to 100 m A. 

Figure 38-4. Examples of three types of missense mutations resulting in abnormal hemoglobin chains. The amino acid alterations and possible alterations in the respective codons are indicated. The hemoglobin Hikari p-chain mutation has apparently normal physiologic properties but is electrophoretically altered. Hemoglobin S has a p-chain mutation and partial function hemoglobin S binds oxygen but precipitates when deoxygenated. Hemoglobin M Boston, an a-chain mutation, permits the oxidation of the heme ferrous iron to the ferric state and so will not bind oxygen at all.

The detection of abnormal hemoglobins In cord blood samples Is usually made with electrophoretic procedures. Four types of hemoglobin variants can be present, namely y-chaln variants, 3-chaln variants, and Hb-Bart s or yif Indicating some form of a-chaln deficiency or a-thalassemla. 

It is perhaps an indication of the limited success of electrophoretic techniques for the determination of pesticide residues at trace levels that although many papers and reviews on the subject have been published, very few laboratories involved in the routine analysis of residues rely on such techniques for their work. Electrophoretic techniques have suffered because of poor flexibility and sensitivities compared with chromatographic techniques. 

These assumptions were confirmed by the electrophoresis study of the washed creams. Electrophoresis of purified fat globules is a convenient method to characterize and quantify proteins adsorbed at the oil-water interface [35]. Electrophoretic data indicate that no casein, nor whey proteins, were adsorbed at the surface of raw-milk fat globule. Upon homogenization, caseins adsorbed preferentially at the lipid-water interface. In this case, bound a-lactalbumin accounted for 16% of the total interfacial proteins. Heat treatment also induced the interaction of proteins with the fat globules. The amount of bound proteins (per mg of lipids) for heated raw milk was half that for homogenized milk. 

Fig. 4. — (a) Gel-Filtration (G. F.) and (b) Electrophoretic (E. P.) Patterns of a Typical, Pig-mucosal Heparin. [Shoulders on the gel-filtration curve (Sephadex G-75, column 180 X 1 cm, 10% Na acetate + 10% EtOH) and bands in the electrophoretograms (cellulose acetate, low amperage, 0.1 Af barium acetate) indicate heparin species differing from each other as regards both mean mol. wt. and degree of sulfation (d.s.). The dashed curve is the electrophoretogram of the fraction of lowest mol. wt. (separated by gel-filtration), accounting for 10% of the total heparin.44]... 

Hereditary deficiency of phosphoglycerate kinase (PGK) is associated with hereditary hemolytic anemia and often with central nervous system dysfunction and/or myopathy. The first case, reported by Kraus et al. (K24), is a heterozygous female, and the results are not so clear. The second family, reported by Valentine et al. (V3), is a large Chinese family, whose pedigree study indicates that PGK deficiency is compatible with X-linked inheritance. To date, 22 families have been reported (04, T25, Y3). Nine of these have manifested both symptoms five have shown only hemolysis seven have shown the central nervous system dysfunction and/or myopathy but without hemolysis and one case, PGK Munchen, is without clinical symptoms (F5). PGK II is an electrophoretic variant found in New Guinea populations (Y2). Red blood cell enzyme activity, specific activity, and the kinetic properties of this polymorphic variant are normal. 

As the redispersion region may be the result of a charge reversal, the electrophoretic mobilities of the MCC sols as a function of NaCl concentration were determined. No charge reversal was detected and the mobility of the particles decreased from 3.5 to 2.6 mobility units in a linear manner with increasing salt concentration indicating that the redispersion region was not caused by charge reversal. 

FIGURE 31-7 Mitochondrial carriers. Ions and small molecules enter the intermembrane space, since the outer mitochondrial membrane is not a significant permeability barrier. However, the inner mitochondrial membrane is impermeable to ions except those for which there are specific carriers. Most of the carriers are reversible, as indicated by two-headed arrows. Compounds transported in one direction are indicated in red. The ATP/ADP translocase and the aspartate-glutamate carrier are both electrophoretic their transport is driven in the direction of the mitochondrial membrane potential, as indicated by red arrows. Glutamine is carried into the matrix by an electroneutral carrier. The unimpaired functioning of mitochondrial carriers is essential for normal metabolism. (Adapted with permission from reference [70].)... 

Salutaridinol 7-O-acetyltransferase was purified to apparent electrophoretic homogeneity from P. somniferum cell suspension cultures and the amino acid sequence of ten endoproteinase Lys-C-generated peptides was determined.28 A comparison of these amino acid sequences with those available in the GenBank/EMBL sequence databases indicated no relevant similarity to known proteins. The first attempt to isolate a cDNA encoding salutaridinol 1-0-... 

Figure 2. Electrophoretic mobility of Corynebacterium versus pH. The general trend of the markers for each KNO3 concentration (A = 0.001 O = 0.01 and x = O.lmoldm-3) is indicated with an auxiliary line. Redrawn from reference [22]...

Our discussion of Section V has indicated that the electrophoretic effect has to be found in the Ta term defined in Eq. (301) (see also Eq. (312)) moreover we have already found a diagram (Fig. 14a) in which the solvent is transmitting the wave number —k from ion /S to ion a, as we expect to find from the classical theory. This term was not calculated in Section V because it gives a contribution of order ei to while the relaxation term is of order e6 it will be considered presently. 

Recent electrophoretic studies46 indicated that the isoelectric point of tomato PM is at pH 6.80 to 6.85. 

A later study (45) indicates that cucurbitin from pumpkin has a molecular weight of TT2,000 dal tons that can be electrophoretically separated into subunits of 63,000 and 56,000 dal tons. Reduction of disulfides produces polypeptides of 36,000 and 22,000 dal tons. Globulins from six cucurbits examined chromatographically (46) have molecular weights of 220,000 to 260,000 dal tons that exhibit predominantly 10.4 - 11.2 S values (about 95% of the three globulin fractions). Cucurbitin from Cucumis sativus appears a tetramer of... 

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