This book presents advanced expression technologies for the production of protein complexes. Since complexes lie at the heart of modern biology, the expression, purification, and characterization of large amounts of high-quality protein complexes is crucial for the fields of biomedicine, biotechnology, and structural biology. From co-expression in E. coli, yeast, mammalian and insect cells to complex reconstitution from individual subunits, this book offers useful insights and guidance for successful protein expressionists. Across several sections readers will discover existing opportunities for the production of protein complexes in bacterial systems (including membrane proteins and cell-free co-expression), methylotrophic and non-methylotrophic yeasts, protozoa (Leishmania terantolae and Dictyostelium discoideum), baculovirus-infected insect cells, mammalian cells, plants and algae. Complex reconstitution from individually purified subunits or subcomplexes is discussed as a complementary strategy. A last section introduces briefly some of the biophysical and structural characterization techniques for macromolecular complexes using state-of-the-art solution scattering and nuclear magnetic resonance. This work is a guided tour over some of the most powerful and successful protein expression technologies, with a focus on co-expression and high-throughput applications. It is addressed to everyone interested in the production and characterization of macromolecular complexes, from university students who want an accessible description of the major co-expression systems to researchers in biomedicine and the life sciences seeking for an up-to-date survey of available technologies.