Sodium dodecyl sulfate reproducibility

Fig. 11. (a) Far ultraviolet rotatory dispersion of ribonuclease. Corrected mean residue specific rotation vs. wavelength [to R = [aLAf/100 [3/(n2 + 2)l where a — specific rotation, M mean residue weight, and n = solvent refractive index. Bars give maximal deviation at peaks. Reproduced from Jirgensons (311). (b) Near ultraviolet rotatory dispersion of 0.48% pancreatic ribonuclease in a 1-mm cell, in (a) 0.15 M phosphate buffer at pH 62 (b) 0.15 M glycine-NaOH buffer at pH 11.5 (c) 0.1 N HC1 (d) 15% sodium dodecyl sulfate. Reproduced from Glazer and Simmons (313). (c) Far ultraviolet circular dichroic spectra of RNase-A, RNase-S, and S-protein at 25° and 3°. Reproduced from Pflumm and Beychok (313). (d) Near ultraviolet circular dichroic spectra of RNase-A as a function of pH. Reproduced from Pflumm and Beychok (313). 

Radiofrequency has been used to titrate sodium dodecyl sulfate with do-decylamine hydrochloride [241] but the method gives a poor reproducibility. It has been claimed that titration with lithium chloride in acetone solution by radiofrequency gives accurate results [242]. 

For many years, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) methods have been used as an essential tool to determine the hydrodynamic size, monitor product purity, detect minor product or process-related impurities, and confirm batch-to-batch consistency of protein and antibody products. ITowever, gel-based techniques have several limitations, such as lack of automation, varying reproducibility, and a limited linear range. SDS-PAGE is also labor-intensive and generates large volume of toxic waste. Most importantly, the technique does not provide quantitative results for purity and impurity determination of proteins and antibodies. 

Fig. 33. A resonance spectrum for a droplet of sodium dodecyl sulfate in water evaporating in dry nitrogen at 293 K. From Measurement of Droplet Interfacial Phenomena by Light-Scattering Techniques, by Daniel C. Tafflin, S. H. Zhang, Theresa Allen and E. James Davis, AIChE Journal, 34, No. 8, pp. 1310-1320, reproduced by permission of the American Institute of Chemical Engineers 1988 AIChE.

A combined effect of natural organic matter and surfactants on the apparent solubility of polycyclic aromatic hydrocarbons (PAHs) is reported in the paper of Cho et al. (2002). Kinetic studies were conducted to compare solubilization of hydro-phobic contaminants such as naphthalene, phenanthrene, and pyrene into distilled water and aqueous solutions containing natural organic matter (NOM) and sodium dodecyl sulfate (SDS) surfactant. The results obtained after 72hr equilibration are reproduced in Fig. 8.19. The apparent solubility of the three contaminants was higher in SDS and NOM solutions than the solubility of these compounds in distilled water. When a combined SDS-NOM aqueous solution was used, the apparent solubility of naphthalene, phenanthrene, and pyrene was lower than in the NOM-aqueous solution. 

A fully automated two-dimensional electrophoresis (2DE) system for rapid and reproducible protein analysis is described. 2DE that is a combination of isoelectric focusing (lEE) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) is widely used for protein expression analysis. Here, all the operations are achieved in a shorter time and all the transferring procedures are performed automatically. The system completed the entire process within 1.5 h. A device configuration, operational procedure, and data analysis are described using this system. 

Figure 8.6 Comparison of the influence of non-ionic Ci2E6 (hexaoxyethyl-ene ft-dodecyl ether) or anionic SDS (sodium dodecyl sulfate) on adsorbed amount of p-lactoglobulin at the air-water interface (0.1 wt% protein, pH = 6, ionic strength = 0.02 M, 25 °C) as determined by neutron reflectivity measurements. Protein surface concentration is plotted against the aqueous phase surfactant concentration ( ) Ci2E6 ( ) SDS. Reproduced from Dickinson (2001) with permission.

FIGURE 6.14. Effect of pretreatment with 1% sodium dodecyl sulfate (SDS) on immunostaining of cultured epithelial cells with anti-AE1/2 affinity-purified antibody at a final concentration of 0.45 i,g/ml. (A) In the absence of SDS treatment, AE2 is barely detectable in MDCK cell cultures. (B) After SDS treatment a bright basolateral membrane staining is visible. Reproduced, with permission, from Brown et al. (1996). Copyright 1996 Springer-Verlag. 

Benturquia et al. [51] described simultaneous determination of vigabatrin and amino acid neurotransmitters in brain microdialysates by capillary electrophoresis and laser-induced fluorescence after precolumn derivatization with naphthalene-2,3-dicaroxaldehyde (NDA). Optimal separation and detection were obtained with a sodium borate buffer (pH 9.2) containing 60 mM sodium dodecyl sulfate and 5 mM hydroxy-propyl-/ -cyclodextrin with fluorescence detection at 589 nm and excitation at 543 nm. The assay was rectilinear over the concentration range of 1.5-200 /(M and the lower limit of detection was 0.13 yM. Both the within-day and day-to-day reproducibilities and accuracies were less than 14.3% and 4.9%, respectively. 

Micellar electrokinetic chromatography (MEKC) is a modality of liquid chromatography having a surfactant molecule in the form of a micelle, which was introduced by Terabe et al. in 1984 [38]. The formation and separation occur in the capillary and, hence, it is also called micellar electrokinetic capillary chromatography (MECC). This modality is useful for some specific molecules having solubilities in micelles and, therefore, utilized for the separation and identification of such compounds with great efficiency, reproducibility, and low levels of detections. The most commonly used compounds for micelle formation are sodium dodecyl sulfate (SDS), sodium tetradecyl sulfate, sodium decanesulfonate, sodium /V-lauryl-/V-mcthyllauratc, sodium... 

Fig. 12-9. Magnetic field dependence of the (0 T) and ks(B) values obtained for (A) BP(benzophenone)/SDS(sodium dodecyl sulfate) system, (B) BP/ Brij 35(a-dodecyl-0)-hydroxypolypoly(oxyethylene) system, (C) NQ(naphthoquinone)/Brij 35 system, and (D) DFBP(decafluorobenzophenone)/Brij 35 system. The S, values estimated with Eq. (12-30) are indicated by the arrows in this figure. The broken lines show the magnetic field dependence of k + k and the dotted lines show the kE values. (Reproduced from Ref. [16b] by permission from The Chinese Chemical Society)...

Schematic representation of the subunit structure of aspartate transcarbamoylase and its dissociation into catalytic and regulatory subunits by mercurials, which can be further converted to inactive monomeric subunits by strong denaturing agents (e.g., sodium dodecyl sulfate). The native enzyme consists of two catalytic trimers placed one above the other, along with three dimeric regulatory subunits surrounding the catalytic trimers in an equatorial plane (a). Substrate maintains the enzyme in the catalytically more active relaxed (R) conformation, while cytidine tripho.sphate maintains it in the catalytically less active taut (T) conformation (b). [Reproduced, with permission from E. L. Smith, R. L. Hill,...

Schematic representations of sodium dodecyl sulfate polyacrylamide gel electrophoretic patterns of red blood cell membranes (M) and membrane skeletons (S), based on work by Fairbanks and Steck. Proteins are stained with Coomassie blue (CB) and sialoglycoproteins with periodic acid-Schiff (PAS). GPA, GPB, and GPC are glycophorin A. B, and C, respectively G3PD is glyceraldehyde-3-phosphate dehydrogenase. (GPA)2 and (GPB)2 are dimers, and GPA-GPB is a heterodiraer. [Reproduced with permission from J. B. Stanbury, J. B. Wyngaarden, D. S. Fredrickson, et al. (Eds.), The Metabolic Basis of Inherited Disease, 5th ed. McGraw-Hill, New York, 1983.]...

In a study of phenacylphenylsulfone photolysis, CIDNP data were taken as evidence that the primary radical pairs cannot recombine to regenerate the starting material because the micelle forces a certain orientation of the radicals [63], From low-field 13C CIDNP and SNP measurements on cleavage of benzylic ketones in sodium dodecyl sulfate micelles, it was inferred [64] that the exchange interaction in these systems is several orders of magnitude smaller ( 10lorads 1 at a reduction distance of 6 A cf. the values in Section IV.B) and the distance dependence is much weaker (a x 0.5 A" cf. the discussion of Eq. 10) than generally assumed for radical pairs. By numerical solutions of the stochastic Liouville equation for a model of the micelle where one of the radicals is kept fixed at the center of the micelle while the other radical is allowed to diffuse, the results of MARY experiments, 13C CIDNP experiments at variable fields, and SNP experiments could be reproduced with the same set of parameters [65],... 

Figure 8. Experimental disjoining pressure isotherm at ambient temperature for sodium dodecyl sulfate (0.001 M) in brine (0.18 MNaCl). (Reproduced from reference 65. Copyright 1992American Chemical Society.)...

Sodium Dodecyl Sulfate-Capillary Gel Electrophoresis (SDS-CGE). SDS-CGE is a capillary-based version of SDS-polyacrylamide gel electrophoresis (SDS-PAGE) in the slab gel format, with advantages of shorter analysis times, ease of automation, and online detection and quantitation [26, 27]. In SDS-CGE, replaceable sieving polymers, such as linear polyacrylamide, poly (ethylene oxide), dextran, or pullulan, are used to achieve reproducible separations. These polymers permit the replacement of a separation matrix for each sample, thereby eliminating cross-contamination between samples and improving reproducibility. Best results are often obtained using chemically or dynamically coated capillaries. 

Fig. 22.2 Summary of the extraction procedure for the SIPC. Bands for molecular weight markers on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) are to the left, and to the right, SIPC subunits. After Clare and Matsumura (2000) reproduced by permission of Taylor Francis Ltd. (www.informaworld.com)...

Figure 6.2. Simultaneous adsorption of a nonionic surfactant, a nonylphenol ethoxylate (NP-EOio) and an anionic surfactant, sodium dodecyl sulfate (SDS), on polystyrene latex. (From B. Jonsson et ai. Surfactants and Polymers in Aqueous Solution, John Wiley, Chichester, 1998, p. 291, Reproduced with permission)...

Figure 6.3. Mole fraction of NP ethoxylate at the particle surface ( ) and in the aqueous phase ( ) as a function of total surfactant concentration in the aqueous phase using a mixture of nonylphenol ethoxylate (NP-EOio) and sodium dodecyl sulfate in a molar ratio of 16 84. (From M. Hulden and B. I onberg, J. Coatings TechnoL, 66, 67 1994, Reproduced with permission of Federation of Societies for Coatings Technology...

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