Efficient delivery of the CRISPR/Cas9 protein complex can be achieved efficiently through the use of cationic lipid-based transfection reagents. Cells may undergo electroporation to increase the probability of successful transfection. Once inside a target cell, the CRISPR/Cas9 protein complex requires no additional stimulation to start modifying the cell’s genome. Genome modification will occur within one day of delivery, while gene and protein expression follows in approximately twelve hours. Altogen recommends using high-purity transfection reagents to minimize the chance of introducing undesired DNA into the cell. Proper protocols should be followed to ensure the purity of sgRNA, which guides the Cas9 protein to a particular location in a cell’s genome. Researchers wishing to add genes to DNA should take precautions to ensure that the repair template is introduced along with the CRISPR/Cas9 complex into the cell during transfection. If a plasmid is used to deliver the CRISPR/Cas9 complex into specific cell line of primary cell type, we recommend using one of Altogen Biosystems cell line optimized transfection kits to encapsulate the plasmid and deliver it into a cell.