Electrophoretic seeding

J. L. Valdes, J. W. Mitchel, J. A. Mucha, L. Seibles, and H. Huggins, Selected-area nucleation and patterning of diamond thin films by electrophoretic seeding, J. Electrochem. Soc., 138 (2) 635-636 (1991)... 

As the separation characteristics of liquid chromatographic and electrophoretic techniques markedly differ from each other, combined methods using the advantages of both procedures have been successfully used for the analysis of flavonoids. Thus, the use of CZE-UV, HPTLC-UV and GC-MS for the measurement of flavonoids in seeds and root exudates of Lotus pedunculatus has been reported. The rooting solution and seed exudate were passed through cellulose acetate filters to bind the flavonoids. After extraction,... 

Yanes and coworkers [43] demonstrated an application of IL for aqueous CE for fhe separation of phenolic compounds (flavonoids) found in grape seed exfracfs. By using [C Qlm] (n = 2,4) ILs as additives for the running electrolyte, a simple and reproducible electrophoretic method for the separation of polyphenols was developed. If was speculated that the separation mechanism was based on an association between the imidazolium cations and the polyphenols. The role of fhe alkyl substituents on the imidazolium cations was investigated and discussed [43]. The anion has little effect on the separation while a related study demonstrated that interaction between phenolic compounds and the IL cations in water occurred through n-n interactions. 

Figure JI. Gel electrophoretic properties of peanut meal proteins that are soluble in suspensions of meal from peanut seeds that were moist heated at various temperatures for different time intervals...

These data demonstrate that changes in foam properties of liquid cyclone processed cottonseed flour are inducible by treatment with succinic anhydride. Gel electrophoretic and solubility data show that there are alterations in the physical and chemical properties of proteins, and in certain cases these changes improve foam properties, that is, improve solubility and polypeptide dissociation of proteins at the interface of the foaming solution. Similar results have been reported for succinylated soybean and sunflower seed proteins (44. 46). 

Thus, differences in functionality of these two suspensions cannot be related to protein quality as distinguished by the gel electrophoretic techniques used in this study. However, these data suggest that solubility of the major storage proteins, or their subunit components, contribute to foam capacity. In addition, other seed constituents, such as carbohydrate and ash (for example, field pea and pecan, respectively) may be equally involved (especially when the suspension pH is 1.5). 

Moreno-Castilla et al. [69] have shown that the adsorption of substituted phenols on activated carbons depends on solution pH. Thus at acidic pH the amount ad.sorbed remained practically con.stant or increa.sed slightly with increasing pH. When the pH increased further, there was a decrease in the amount adsorbed the pH at which this decrease took place depended on the difference between the external and internal surface charge density as measured by electrophoretic and titration measurements, respectively. A sharp turn toward a more substantive discussion of coupled pH and surface chemistry effects thus occurred in the mid-1990s, and these publications are analyzed below. The seeds for such a discussion were planted much earlier, however, and we analyze first how and why it took decades for them to flourish. 

Fairbanks, D., Burgener, K., Robison, L., Andersen, W., and Ballon, E. (1989). Electrophoretic characterization of quinoa seed proteins. Plant Breeding 104(3), 190-195. 

Northern analysis (Alwine et al., 1977, 1979) of RNA after electrophoretic fractionation was initially carried out on diazotized (DBM) paper, but its detection limit was only about 500 pg RNA (using a probe of 10 cpm/ xg). Subsequently, Thomas (1980, 1983) succeeded in detecting less than 1 pg on nitrocellulose. Diazotized (APT) paper was also found to be superior to DBM paper (Seed, 1982), however nitrocellulose and charged nylon (Reed and Mann, 1985) have become the preferred membranes. RNA can be detected at less than 0.01% (10 xg loaded) on nitrocellulose or, particularly on nylon which usually has an increased background, however. Nylon membranes are required if reprobing is desired. 

Animals were inoculated with Enterobacter cloacae and hemolymph was collected as described (11,12). Hemolymph proteins were separated by isoelectric focusing (IEF) on LKB PAG plates at pH 3.5-9.5 according to the manufacturers instructions. To detect antibacterial activity after IEF, the electrophoretic plates were overlaid with phosphate buffered LB agar seeded with E coli strain D31. The antibacterial factors diffused from the IEF plate into the bacteria-containing overlay thus blocking bacterial growth and revealing bands of activity (13). 

The seeding can be performed under vacuum [102] or by electrophoretic deposition in aqueous or non-aqueous medium [103]. The latter method has been applied to the rapid synthesis of A-type zeolite membranes. Two strategies can be used for an electrostatic attachment of the seeds to the support either a fine-tuned surface charge by pH control and measurement of the support zeta-potential or the adsorption of positively charged polymers [104], and immersion in a suspension whose pH is such that the seed particles are negatively... 

The insect cells were seeded in 2.5 ml of complete TClOO medium as described above. After the cells had attached, a viral inoculum (200-400 jj,l) was added to the cells. At the same time, a mixture of [ Sjmethionine and cysteine (0.5 mCi per 25-cm culture flask) was added to the medium. The time course of intracellular radioactive incorporation into total protein was analyzed over 72 hr. The cells were harvested and washed three times with cold PBS. The final cell pellet was resuspended in 300 /xl of lysis buffer, boiled for 5 min, and stored frozen at — 20°C for later analysis. Proteins were analyzed on 10% SDS-PAGE using 5-10 /jlI of the lysate. Radioactive incorporation into protein was detected after fluorography using EN HANCE (DuPont de Nemours) according to the manufacturer s protocol. Exposure of the dried gel on X-ray film was followed by laser densitomet-ric quantification. In parallel, after electrophoretic separation of the proteins, the gel was stained with Coomassie Brilliant Blue and dried, and the respective recombinant proteins were then cut out with a razor blade. Specific radioactive incorporation was measured by liquid scintillation counting. 

Magni C, Herndl A, Sironi E, et al. (2005b). One- and two-dimensional electrophoretic identiheation of IgE-binding polypeptides of Lupinus albus and other legume seeds. J. Agric. Food Chem., 53 4567-4571. 

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