Fig. 1

CRISPR/Cas9-engineered hESCs demonstrate stable ferritin overexpression. a Schematic of the plasmid vector for inserting the human ferritin transgene into the AAVS1 locus in the genome of hESCs ESI-017 using a non-viral CRISPR/Cas9 system. b Immunofluorescence imaging confirmed gene insertion with eGFP tag (green). Cell nuclei were stained by Hoechst 33342 (blue). Scale bar = 50 μm. c Western blot confirmed ferritin overexpression in hESCs relative to wild type (WT); β-actin was used as loading control. Full-length blots are presented in Additional file 1: Fig. S1. d Cellular iron uptake measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) confirmed the functionality of ferritin. Cells were supplemented with 1.0 mM ferric ammonium citrate for 24 h. Data are presented as mean ± SEM (n = 3). ** P < 0.01