Cross-linked polyacrylamide gels

Alcosorb 400 Water-Retaining Polymer," undated product Hterature, AHied CoUoids describes agricultural uses of cross-linked polyacrylamide gels. 

Widhalm, A., Schwer, C., Blaas, D., Kenndler, E. (1991). Capillary zone electrophoresis with a linear, non-cross-linked polyacrylamide gel separation of proteins according to molecular mass. J. Chromatogr. 549, 446 451. 

Capillary gel electrophoresis (CGE) is a specialised form of CE that employs a fused silica capillary filled with an immobilised and cross-linked polyacrylamide gel. This gel contains a network of pores, which allows separation of ions based on differences in molecular size. CGE was applied to the separation of ionic alkylphenol ethoxy sulfates and... 

Polymer Network Studies Using Piiramagnetic Probes Cu(II) in Cross-Linked Polyacrylamide Gels... 

Figure 1. ESR spectra of Cu(II) at X-band and 77 K in chemically cross-linked polyacrylamide gels with pore diameters of 1.3 nm (A) and 4.0 nm (B). Solid lines are experimental spectra dotted lines are spectra calculated using the appropriate values of AH, and given in Table I and with 2.408, gj = 2.080, A,= 0.0134 cm, Aj,= 0.0009 cm, and AH = 30.0 Gauss.

Figure 5. ESR spectra of Cu(II) at X-band in chemically cross-linked polyacrylamide gels with pore diameter of 0.7 nm as a function of temperature. The appearance of the quartet centered g-iso is visible above 245 K.

Figure 12.12b illustrates the application of gel electrophoresis to protein characterization. In this illustration a cross-linked polyacrylamide gel is the site of the electrophoretic migration of proteins that have been treated with sodium dodecyl sulfate. The surfactant dissociates the protein molecules into their constituent polypeptide chains. The results shown in Figure 12.12b were determined with well-characterized polypeptide standards and serve as a calibration curve in terms of which the mobility of an unknown may be interpreted to yield the molecular weight of the protein. As with any experiment that relies on prior calibration, the successful application of this method requires that the unknown and the standard be treated in the same way. This includes such considerations as the degree of cross-linking in the gel, the pH of the medium, and the sodium dodecyl sulfate concentration. The last two factors affect the charge of the protein molecules by dissociation and adsorption, respectively. Example 12.5 considers a similar application of electrophoresis. 

EXAMPLE 12.5 Estimation of Number of Nucleotides in Glycine tRNA Using Electrophoresis. Synthetic DNA standards and RNA molecules were electrophoresed in 7 M urea solution on cross-linked polyacrylamide gels (Maniatis et al. 1975). A semilog plot of the number of nucleotides versus the mobility relative to xylene cyanol FF dye is linear and includes the points (N = 100, u i = 0.33) and (N = 50, urei = 0.55). Estimate the number of nucleotides in the glycine tRNA molecule of Staphylococcus epidermidis if it shows a relative mobility of 0.16. 

Polyurethane Hydrogel Cross-Linked Polyacrylamide Gels Cross-Linked Polyacrylic Acid Gels... 

What is the cross-linking agent used for producing a cross-linked polyacrylamide gel (2 marks)... 

Ugaz, V.M., Brahmasandra, S.N., Burke, D.T., Burns, M.A., Cross-linked polyacrylamide gel electrophoresis of single-stranded DNA for microfabricated genomic analysis systems. Electrophoresis 2002, 23, 1450-1459. 

Herr, A.E., Singh, A.K., Photopolymerized cross-linked polyacrylamide gels for on-chip protein sizing. Anal. Chem. 2004, 76, 4727-4733. 

The application of CE-LIF using intercalating dyes TOTO-1 and YOYO-1 (with a sample prestaining procedure) and separation systems employing either polymer network (0.5% methylcellulpse) or cross-linked polyacrylamide gel (3%T, 3%C) was also reported by Srinivasan et al. (1993). Excellent sensitivity (about 500 pg/mL) was reported besides, it was found that the polymer network capillaries have a broader DNA size range of effectiveness and provide higher resolution and efficiency than gel-filled capillaries. 

Separation matrices mainly used for the separation of DNA by capillary electrophoresis are gel or polymer solutions as listed in Table 1. The separation of singlestrand oligonucleotide is achieved by using cross-linked polyacrylamide gel, in which the concentration varies from 3% to 8% T and the degree of cross-linking varies from 3% to 5% C. High-concentration linear polyacrylamide (8-10%) has been successfully applied... 

For example, urease, together with a buffered electrolyte, might be held in a cross-linked polyacrylamide gel. When the electrode is immersed in a test solution, there will be a selective response toward urea, which diffuses through the diaphragm into the gel. The response comes about because the urease catalyzes the process ... 

LDR products (44 and 51 bp) were analyzed by a cross-linked polyacrylamide gel (5%T/5%C) in approximately 45 min having a 1000-fold molar excess of the LDR primers (25 bp). Interestingly, when linear polyacrylamide gels were used, these same fragments could not be detected because of significant electrokinetic bias during the electrokinetic injection process. 

Single base resolution using cross-linked polyacrylamide gel-filled capillary Sequencing using a four-color CE-LlF system Replaceable gels introduced... 

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