Abstract
Genome-wide functional genomic screens utilizing the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system have proven to be a powerful tool for systematic genomic perturbation in mammalian cells and provide an alternative to previous screens utilizing RNA interference technology. The wide availability of these libraries through public plasmid repositories as well as the decreasing cost and speed in quantifying these screens using high-throughput next-generation sequencing (NGS) allows for the adoption of the technology in a variety of laboratories interested in diverse biologic questions. Here, we describe the protocol to generate next-generation sequencing libraries from genome-wide CRISPR genomic screens.