With increasing applications of nanoparticulate colloids in science and industry, it becomes increasingly important to obtain a profound understanding of their physical, chemical and biological effects. The agglomeration state and the agglomeration kinetics of such colloidal nanoparticle suspensions are important parameters in assessing the physical properties of these systems. Moreover, the detailed agglomeration behaviour of nanoparticles in presence of molecular species is far from being completely understood. This leads to many problems in scientific and industrial applications of nanoparticulate material and makes the prediction and assessment of biological effects that these NPs have a fast growing field of contemporary research. As nanoparticles are of the same size scale as typical cellular components and proteins, such particles are suspected to evade the natural defences of the human organism and may lead to permanent cell damages. Numerous toxicological studies have revealed that nanoparticles are much more reactive and toxic than larger particles made from the same material. It is therefore of paramount interest to characterize NP suspensions in salt containing environments and to ultimately also assess the influence of biomolecules on their behaviour.