CRISPR/Cas9 system consists of a “guide” RNA (gRNA) and a bacterial CRISPR-associated endonuclease (Cas9). The gRNA is a short synthetic RNA composed of a Cas9-binding “scaffold” sequence and ∼20 nucleotide “targeting” sequence that defines the target genomic site to be modified. Cas9 contains two nuclease domains to induce site-specific DNA cleavage. It’s a scalable genome-wide editing technology for its ease of generating gRNAs. The simplicity and high-efficiency of CRISPR/Cas9 system make it a preferable genomic knockout method to the traditional ZFN and TALEN system. Our scientists are experts at performing gene knockout with CRISPR/Cas9, from designing gRNA constructs to transfection and single clone generation of a wide range of cells, including difficult-to-transfect and tumor cell lines.