Genome engineering with custom recombinases

Site-specific recombinases are valuable tools for myriad basic research and genome engineering applications. In particular, hybrid recombinases consisting of catalytic domains from the resolvase/invertase family of serine recombinases fused to Cys2-His2 zinc-finger or TAL effector DNA-binding domains are capable of introducing targeted modifications into mammalian cells. Due to their inherent modularity, new recombinases with distinct targeting specificities can readily be generated and utilized in a "plug-and-play" manner. In this protocol, we provide detailed, step-by-step instructions for generating new hybrid recombinases with user-defined specificity, as well as methods for achieving site-specific integration into targeted genomic loci using these systems.