Agarose selection

Various support media may be employed in electrophoretic techniques. Separation on agarose, acrylamide, and paper is influenced not only by electrophoretic mobiUty, but also by sieving of the samples through the polymer mesh. The finer the weave of selected matrix, the slower a molecule travels. Therefore, molecular weight or molecular length, as well as charge, can influence the rate of migration. 

Phosphoproteins (various). Purified by adsorbing onto an iminodiacetic acid substituted agarose column to which was bound ferric ions. This chelate complex acted as a selective immobilised metal affinity adsorbent for phosphoproteins. [Muszyfiska et al. Biochemistry 25 6850 1986.]... 

E.coli K12 TGI were grown to log phase (up to OD6oo=0.20-0.30) in Luria-Bertani (LB) broth, washed and ultimately concentrated 25 times in ice-cold 100 mM of CaCb. DNA was extracted from agarose gel after electrophoresis, added to 200 ml of competent cell and incubated at 0°C for 15 min. The cell-DNA complex was transferred to 42°C for exactly 90 s and was rapidly chilled in ice. Then 1000 ml LB-broth was added and the cells were incubated at 37°C for 60 min. 100 ml cells was spread on LB-agar with and without selective marker ampicillin (50 mg/ml), to obtain the number of transformants and viable cells respectively. Plates were incubated at 37°C for 18-24 h. 

TES-45 and TES-55 are two glycoproteins that have yet to be identified at a genetic level, but evidence has been obtained that they may also be lectins. Carbohydrate affinity chromatography with mannose-agarose shows that TES-32 selectively binds as expected, but that TES-45 is also present in small amounts (Loukas et al., 1999) unlike TES-32, TES-45 does not bind to A -ace Lylgalac t< isamine. No sequence information has yet been obtained on TES-45, but it is recognized by polyclonal antibodies generated to TES-32,... 

Though electrophoretic separations were historically first studied in free solutions, more recent developments have extended its application to solid supports, including polyacrylamide, agarose, and starch gels. The purpose of a solid support is to suppress convection current and diffusion so that sharp separations may be retained. In addition, support gels of controlled pore sizes can serve as size-selective molecular sieves to enhance separation - smaller molecules experience less frictional resistance and move faster, while larger molecules move slower. Therefore, separation can be achieved based on molecular size. 

Fig. 5. Thirty-four out of 35 potential apo(a) isoforms, separated by SDS-agarose gel electrophoresis. The photograph represents a composite of two separate gels with the reference mixture (St) and 17 different samples applied to each gel. Samples were selected to represent each of the observed isoforms. Twenty-nine samples had single-handed patterns and five samples had double-banded patterns. The double banded types and every fifth single-handed phenotype are indicated at the bottom of each gel lane. [With permission of Marcovina et al. (M12).]...

Following the TSA-based strategy, RNA aptamers were selected that specifically complexed the TSA for the isomerization of an asymmetrically substituted biphenyl derivative (Scheme 1) [7]. The selection was performed by affinity chromatography of a randomized pool on the TSA immobilized on agarose. After seven rounds of selection, the RNA pool accelerated the basal reaction 100-fold and was completely inhibited by the planar TSA. 

While the binding of aminoglycosides to the RRE provides a proof of principle, their affinity and, in particular, selectivity traits need to be improved for true therapeutic utility. To facilitate the discovery of potent and selective RRE binders, we developed a solid-phase assay. The components of this assembly include (a) insoluble agarose beads (or microtiter plates) covalently modified with streptavidin, (b) a biotinylated RRE fragment, and (c) a fluorescein-labeled Rev fragment (RevFl). Assembly of the three components generates an immobilized ternary complex whereby the biotinylated RRE binds to the beaded... 

Selected entries from Methods in Enzymology [vol, page(s)] Determination of FMN and FAD by fluorescence titration with apoflavodoxin, 66, 217 purification of flavin-adenine dinucleotide and coenzyme A on p-acetoxymercurianiline-agarose, 66, 221 a convenient biosynthetic method for the preparation of radioactive flavin nucleotides using Clostridium kluyveri, 66, 227 isolation, chemical synthesis, and properties of roseoflavin, 66, 235 isolation, synthesis, and properties of 8-hydroxyflavins, 66, 241 structure, properties and determination of covalently bound flavins, 66, 253 a two-step chemical synthesis of lumiflavin, 66, 265 syntheses of 5-deazaflavins, 66, 267 preparation, characterization, and coenzymic properties of 5-carba-5-deaza and 1-... 

Figure 3. Summary of the selection procedure for cutinase-defective mutant. The T-8 strain of F. solani was mutagenized by ultraviolet irradiation, grown for 3 days, and plated on medium containing 0.5% acetate and agarose for 5-7 days to permit colony formation. Subsequently, the colonies were overlaid with an agarose solution containing 1.26 mM PNB. The parental colonies hydrolyzed the substrate and turned yellow while the presumptive mutant colonies remained white and were selected for analysis. Further details are given in Ref. 13.

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