Recombinant therapeutic protein expression using mammalian platforms can be achieved using a range of workflows optimized for different objectives. These processes include transient transfection, and the creation of stable pools and clonal cell lines. Transient and stable pool processes are generally used for discovery through early-stage development to enable rapid production and screening of large numbers of protein candidates, while stable clonal cell lines are used for GMP clinical and commercial manufacturing. In this white paper, we describe how GS Discovery^® provides optimized transient expression processes to support early stage expression of a range of therapeutic proteins.