The Weiss Laboratory seeks to create integrated biological systems capable of autonomously performing useful tasks, and to elucidate the design principles underlying complex phenotypes. Cells sense their environment, process information, and continuously react to both internal and external stimuli. The construction of synthetic gene networks can help improve our understanding of such naturally existing regulatory functions within cells. Synthetic gene networks will also enable a wide range of new programmed cells applications. We use computer engineering principles of abstraction, composition, and interface specifications to program cells with sensors and actuators precisely controlled by analog and digital logic circuitry.