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 100 μL size is sufficient for creating stable Cas9 expressing pools of cells or for isolating stable Cas9 expressing clones. LentiArray Cas9 Lentivirus is provided as ready to use lentivirus at a titer of 1 x 10⁷ TU/mL.