The Litesizer 500 is a measuring instrument in which dynamic light scattering (DLS), electrophoretic light scattering (ELS), and static light scattering (SLS) are combined in a compact structure. This combination enables the Litesizer 500 to determine a range of important paramaters for particles, droplets and macromolecules dispersed in liquid, including:

• particle size (hydrodynamic diameter and size distribution)
   
• particle charge and the chemical surface functionalities of the particles via the zeta potential and zeta potential distribution
   
• molecular masses of polymers, proteins and nanoparticles
   
• particle interactions from the second virial coefficient
   
• turbidity of the sample (transmittance at 658 nm)
   
• refractive index of the continuous medium (using known references)

Note that sample concentrations should not be too high, or your measurement may suffer from "multiple scattering" effects that skew the size results. Typically a particle concentration of < 0.1 % v/v is a good starting point, but the optimum approach is to check a concentration range and choose a concentration within the range where the size result remains consistent.

Zeta potential determination with the ELS mode requires special cuvettes with electrodes (see "Omega cuvette details" document and link to consumable to order from the supplier). The gold electrodes to the Omega cuvette easily corrode in salt solutions above ~ 20 mM or extremes of pH. There is an expensive accessory called the "Univette" that can be used to measure zeta potential of higher salt concentrations and that is much more chemically resistant (contact the tool responsible if that is of interest). 

Technical specifications