The high content screening (HCS) and analysis unit consists of a robot for the preparation and processing of samples, a fully automated HCS microscope, software for image acquisition and for data analysis, storage capabilities for large data sets and two genome-wide siRNA libraries (human & mouse). The unit is designed for large-scale image-based screens. It complements cell-based siRNA analysis pursued by several groups at the FLI, emphasizing functional assays on genome-wide level. Installation began in early 2008. Extensive training contracts for scientific and technical personnel ascertain the high level of expertise required for designing and performing large-scale screens.