Dynamic light scattering (DLS) is used to measure the size of small particles in suspension and of macromolecules in solution. When light is passed through such a sample, the particles scatter the light. Because the particles are constantly moving, the scattering intensity in any one direction fluctuates according to the particles' velocity. Since a particle's velocity depends on its size, the particle size in a given sample can be derived from DLS measurements. In this Application Report, we use polymer latex spheres ranging from 22 nm to 9200 nm in diameter to verify the DLS performance.