The stability of colloidal particle dispersions is a mainstay of colloid science. Although the DLVO theory still provides much of the guidance for assessing the stability of aqueous dispersions, significant further advancements were made on recognizing that colloidal dispersions in many situations behave as equilibrium systems, which furnishes a solid starting point for investigating limits of stability. For instance, dilute and dense fluid phases, as well as crystal phases, analogous to gas, liquid, and solid phases in molecular systems, appear in the equilibrium phase diagram. However, in contrast to simple molecular systems, colloidal systems exhibit non-crystalline, solid-like structures of non-equilibrium but exceptionally long-lived character, so-called gels. These appear across a host of colloidal systems, including dispersions of sterically stabilized colloids, star polymer solutions, and block copolymer micellar systems, either in marginal solvents or interacting via a depletion mechanism in the presence of additives like non-adsorbing polymer. Also, solutions of globular proteins exhibit similar behavior in some instances. Model systems occupy an important role in science. New phenomena can be studied systematically under controlled conditions and they provide the proving ground for new concepts and theory. In this project we are developing new, water-borne colloidal model systems for studies of gelation. The goal is to obtain nearly refractive index matched particles suitable for experimental studies by laser light scattering. These experiments are designed to shed light on the nature of the gelation phenomenon and its connection to phase separation and particle clustering.