A resource for large-scale RNA-interference-based screens in mammals.

Gene silencing by RNA interference (RNAi) in mammalian cells using small interfering RNAs (siRNAs) and short hairpin RNAs (shRNAs) has become a valuable genetic tool. Here, we report the construction and application of a shRNA expression library targeting 9,610 human and 5,563 mouse genes. This library is presently composed of about 28,000 sequence-verified shRNA expression cassettes contained within multi-functional vectors, which permit shRNA cassettes to be packaged in retroviruses, tracked in mixed cell populations by means of DNA 'bar codes', and shuttled to customized vectors by bacterial mating.