Engineering of human embryonic stem cells (hESC) offers a great potential tool for the study of human gene function. There are many techniques that can be used to engineer human cells, but most are lacking in either specificity or efficiency. Jump-In™ TI™ technology utilizes two bacteriophage recombinases (PhiC31 and R4) to specifically, efficiently, and stably introduce genetic elements into the genome of human ESCs. The techniques described here allow the user to first deliver a targeting site to a defined locus, and second to deliver the genetic elements of interest to that targeting site, allowing for stable, single copy integration into the genome. These integrated elements show high levels of expression in the pluripotent state, as well as in multiple differentiated lineages.
