Zygote Electroporation for CRISPR/Cas9 Delivery to Generate Genetically Modified Mice

The CRISPR/Cas9 system is a powerful tool for generation of genetically modified mice. In conventional protocols, Cas9 protein (or mRNA) and sgRNA are introduced into zygotes by microinjection. However, microinjection requires special skill and is too time-consuming to treat zygotes on a large scale. Recently, we have developed a simple electroporation method which generates genetically modified mice with high efficiency. Here, we describe our method GEEP (genome editing by electroporation of Cas9 protein). This method facilitates high-throughput genetic analysis of the mouse. This chapter describes the GEEP method to generate genetically modified mice.