High-content siRNA screening for target identification and validation

Background: Automated microscopy and image analysis have progressed tremendously over the past 10 years and opened up a new era of highcontent screening. In parallel, RNA interference (RNAi) has revolutionized the functional analysis of genes. Objective: The focus of this review is screening of RNAi libraries, and in particular in screening of short interfering RNA (siRNA) libraries for target identification and validation in mammalian cell systems. Methods: Recent literature of high-content siRNA screening in oncology, in intracellular trafficking and infection biology, and in neurobiology is reviewed and placed in the context of a discussion on hit verification. Results/conclusion: Various methods have been established for the application of RNAi in mammalian cells also, which allows efficient and reproducible silencing of individual genes to gain functional information on each individual gene. Complex multi-para metric cell-based assays, combined with both technologies, provide an extraordinary valuable tool to help understand biological and pathological processes in a systematic way and discover new targets for pharmaceutical exploitation.