We recently demonstrated that the zygotic gene Zscan5bis involved in maintaining the genomic integrity of pluripotent stem cells (PSCs) during mitosis and that Zscan5bgene expression can prevent chromosomal abnormalities. Here, we provide a detailed protocol for the transfection of mouse embryonic stem cells (mESCs) and mouse-induced PSCs (miPSCs) with a Zscan5bconstitutive expression plasmid, using the piggyBac transposon gene expression vector system.