Visualization of homozygous hsa-miR-302/367 knockout cells. (A) Schematic image of Homo sapiens (hsa)-miR-302/367 cluster knockout (KO) by CRISPR/Cas9 technology. Donor vectors for homologous recombination were designed to show green and red fluorescent signals in case recombination occurred homozygously. (B) Time-lapse imaging after tRFP donor plasmid transfection into a green fluorescent protein (GFP)-positive heterozygous hsa-miR-302/367 knockout Edom_iPSCs. White arrowhead indicates a tRFP/GFP doble-positive cell. is EGFP, enhanced green fluorescent protein; hetero KO, heterozygous knockout; homo KO, homozygous knockout; iPSC, induced pluripotent stem cell; LHA, left homologous arm; RHA, right homologous arm; tRFP, turbo red florescent protein.