Recent Advances in DLS and DPI. Dave Dolak, Malvern Instruments RAMC 2007, San Diego. Classical vs. Backscatter Dynamic Light Scattering (DLS). Backscatter Optics.
Recent Advances in DLS and DPI
Dave Dolak, Malvern Instruments
RAMC 2007, San Diego
Backscatter optics facilitate a variable cell position, accommodating both high & low concentration samples. The increased scattering volume ensures high sensitivity, without compromising the working size range or needing to resort to high power lasers which can lead to thermal convection.
High resolution from chromatography separation+
Ease of use with dynamic light scattering
DPI stacks two waveguides together--separated by a spacer – which yields an interference pattern at the end of the waveguides. If one waveguide is used as the experimental surface, then changes in the interference pattern can be analyzed to deduce what is happening at the adsorbed layer when various materials are adsorbed to it or as those adsorbed materials change.
Rest of sensor chip structure including reference waveguide
DPI offers the ability to quantify changes in the thickness and density (to the sub-Angstrom level) on the chip surface.
Sensitive to sub-Angstrom changes in size at picogram concentrations--can detect onset of crystallization at nucleation.
Shape orientation, binding & conformational changes
Dual Polarization Interferometry (DPI) confirms specific binding of Biotin with Streptavidin and resulting conformational change.
The Truth Is Out There
DLS and DPI offer new insights into macromolecular behavior.