Dynamic light scattering analysis

Habel, J. E., Ohren, J. R and Borgstahl, G. E. (2001). Dynamic light-scattering analysis of full-length human RPA14/32 dimer purification, crystallization and selfassociation. Acta Crystallogr. D 57, 254-259. 

Moradian-Oldak. J. Leung, W. Fincham, A.C. Temperature and pH-dependent supramolecular self-assembly of amelogenin molecule A dynamic light scattering analysis. J. Struct. Biol. 1998. 122. 320-327. 

FIGURE 20.27 (a) Dynamic light scattering analysis of the size distribution of chitosan nanoparticles (CSNPs) by using (A) a PCTE... 

FIGURE 8.22 Hydrodynamic radius of PPy-DBSA in chloroform containing different amounts of extra DBSA at 25°C, where the concentration of PPy-DBSA is 0.01 g/dL The inset shows autocorrelation functions obtained from the dynamic light scattering analysis. (From Song, K.T., Synthesis of electrically conducting soluble polypyrrole and its characterization. Ph.D. thesis, 2000. With permission.)... 

Rodriguez, R.,Vargas, S., Femandez-Velasko, D.A 1998. Reverse micelle systems composed of water, Triton XlOO and phospholipids in organic solvents. 1. Phase boundary titrations and dynamic light scattering analysis. J. Colloid Interface Sci. 197, 21. 

Dynamic light-scattering experiments or the analysis of some physicochemical properties have shown that finite amounts of formamide, A-methylformamide, AA-dimethyl-formamide, ethylene glycol, glycerol, acetonitrile, methanol, and 1,2 propanediol can be entrapped within the micellar core of AOT-reversed micelles [33-36], The encapsulation of formamide and A-methylformamide nanoclusters in AOT-reversed micelles involves a significant breakage of the H-bond network characterizing their structure in the pure state. Moreover, from solvation dynamics measurements it was deduced that the intramicellar formamide is nearly completely immobilized [34,35],... 

Dynamic image analysis systems, 18 147 Dynamic Kerr effect (DKE), 17 454 Dynamic light scattering (DLS), 20 381 in molecular weight determination,... 

Antibiotic Mg complex induced alteration in the ultrastructural changes in the native and HI depleted chromatin were monitored by thermal melting analysis, polyacrylamide gel mobility assay, dynamic light scattering experiments and transmission electron microscopic studies. Micrococcal nuclease digestion is the biochemical probe to assess the accessibility of the antibiotic Mg + complexes to nucleosomal DNA. 

Methods for analysis of the particle size distribution in the aerosol cloud include techniques such as time of flight measurement (TOE), inertial impaction and laser diffraction. Dynamic light scattering (photon correlation spectroscopy) is confined to particles (in suspension) in the submicron range. In addition to the size distribution, the particle velocity distribution can be measured with the Phase Doppler technique. 

Analysis of polyelectrolytes in the semi-dilute regime is even more complicated as a result of inter-molecular interactions. It has been established, via dynamic light-scattering and time-dependent electric birefringence measurements, that the behavior of polyelectrolytes is qualitatively different in dilute and semi-dilute regimes. The qualitative behavior of osmotic pressure has been described by a power-law relationship, but no theory approaching quantitative description is available. 

It is our objective in this chapter to outline the basic concepts that are behind sedimentation and diffusion. As we see in this chapter, gravitational and centrifugal sedimentation are frequently used for particle-size analysis as well as for obtaining measures of solvation and shapes of particles. Diffusion plays a much more prevalent role in numerous aspects of colloid science and is also used in particle-size analysis, as we see in Chapter 5 when we discuss dynamic light scattering. The equilibrium between centrifugation and diffusion is particularly important in analytical and preparative ultracentrifuges. 

In contrast to traditional dynamic light scattering (which, as we discuss in Section 5.8, probes the continuous random motion of the particles), DWS here probes spatially localized, temporally intermittent events that are characterized by relatively larger length scales. Despite this, the basic quantity measured (g,(trf) in the notation of Section 5.8 there is no angular dependence in DWS because of multiple scattering) is essentially the same, only the method of analysis is different. 

EXAMPLE 5.5 Determination of the Effective Diameter of an Enzyme Using Dynamic Light Scattering. DLS analysis of a dilute solution of the enzyme phosphofructokinase in water at T = 293K leads to the following data for the correlation function g2(s,td) ... 

The use of photon correlation spectroscopy to study the dynamics of concentration fluctuations in polymer solutions and gels is now well established. In bulk polymers near the glass transition there will be slowly relaxing fluctuations in density and optical anisotropy which can also be studied by this technique. In this article we review the development of the field of photon correlation spectroscopy from bulk polymers. The theory of dynamic light scattering from pure liquids is presented and applied to polymers. The important experimented considerations involved in the collection and analysis of this type of data are discussed. Most of the article focuses on the dynamics of fluctuations near the glass transition in polymers. All the published work in this area is reviewed and the results are critically discussed. The current state of the field is summarized and many suggestions for further work are presented. 

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