Dynamic Light Scattering Instrumentation (DLS) We have recently
expanded our light scattering service by implementing DYNAMIC
LIGHT SCATTERING instrumentation. Although this approach does
not provide the precision possible with static light scattering
detection, the measurement requires small amounts of protein
(minimal amount for a protein of MW ~40 kDa is 25 microliters of
a sample with ~0.5 mg/ml). The measurement is faster than during
static light scattering measurement and, most importantly,
sample does not experience any dilution during measurement. The
DLS experiment measures time fluctuations of light intensity
caused by motions of macromolecules in solution. How rapidly the
intensity fluctuates over time is represented by an
autocorrelation function. Analysis of the correlation function
decay as a function of short time intervals can be used to
evaluate the translational diffusion coefficient, D. The
hydrodynamic radius, Rh, can be then calculated from D using the
Stokes-Einstein equation. Additional