Each technique has its advantages and disadvantages for characterizing different properties of the analyte. Light scattering is a technique that can be applied in either batch or chromatography mode.
DLS measurements can determine the diffusion coefficient of macromolecules or particles, from which the hydrodynamic radius is calculated.
Dynamic Light Scattering ( DLS) or Quasi-elastic Light Scattering (QELS) - In a DLS measurement, time-dependent fluctuations in the scattered light signal are measured using a fast photon counter.Via the concentration dependence of the scattered intensity, it is possible to quantify molecular interactions as the second virial coefficient ( A 2, for non-specific interactions) or equilibrium dissociation constant ( K D, for non-specific interactions). For certain classes of particles having sizes in the vicinity of the wavelength of the incident light, MALS can help determine shape and structure. For macromolecules much smaller than the wavelength of the incident light, the data are analyzed to determine the molar mass or molecular weight M w and rms radius R g. Multi-Angle Light Scattering ( MALS), Static Light Scattering (SLS) or Classical Light Scattering - In MALS the intensity of the scattered light is measured as a function of angle.Wyatt instruments make two different types of light scattering measurements for absolute molecular characterization: In this sense it is an absolute measurement. In contrast to most methods for characterization, it does not require outside calibration standards. Light scattering comprises a versatile suite of non-invasive techniques for characterizing macromolecules and a wide range of particles in solution. Dynamic & Electrophoretic Light Scattering.
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