The Cre-lox system is used to introduce deletions, insertions, translocations, and inversions at a specific genomic locus. The system utilizes Cre recombinase, a bacteriophage P1 enzyme that recognizes a short target DNA sequence (loxP site). The AAVpro Helper Free System (AAV2-CRE Recombinase) is a kit for the preparation of serotype 2 adeno-associated virus (AAV2) viral particles to deliver the Cre recombinase gene cassette to mammalian cells. High-titer AAV2 particles can be prepared without a helper virus. HEK 293T cells are transfected with plasmids encoded in this kit, and AAVpro Extraction Solution is used for efficient AAV2 particle isolation.