LentiArray Cas9 Lentivirus provides an efficient method to drive high level Cas9 nuclease expression in a wide variety of cell types. The LentiArray Cas9 Lentivirus construct includes a human codon-optimized version of Cas9 with two nuclear localization signals to facilitate efficient delivery into the nucleus. The 1-mL size is designed to support studies utilizing a co-infection approach (Cas9 lentivirus + guideRNA lentivirus delivered together) with either the LentiArray CRISPR libraries or LentiArray gRNAs against single gene targets. LentiArray Cas9 Lentivirus is provided as ready to use lentivirus at a titer of 1 x 10⁷ TU/mL.