Numerous synthetic, low molecular weight compounds like organic azo-dyestuffes form fiber-like aggregates in solution in close analogy to proteins of living cells. The underlying processes can be regarded as physical polymerisations with a structural diversity, which is just as large as the complexity observed in macromolecular chemistry. In order to reveal general principles on this self-assembly, several low molecular weight systems like anionic azo-dyestuffs have been selected for a detailed investigation with time resolved LS. These systems shall be compared with the behaviour of Ab-amyloid responsible for the Alzheimer disease as well as the proteins which establish the cytoskeleton. It is the final goal to unravel aggregation mechanisms and to develop tools to control aggregate size, size distribution and aggregate morphology.