Fig. 2.

geNOps functionality correlates with cellular iron (II) uptake. a, Representative electron micrographs of HEK293T cells stained with Perls/DAB under control condition (1^st image), treated with 1 mM ascorbate (2^nd image), treated with 1 mM FeSO₄ (3^rd image), or treated with 1 mM FeSO₄ + 1 mM ascorbate (4^th image). Pink arrows indicate accumulated iron particles. Scale bars indicate 10 μm b, Representative low-magnification images of HEK293T cells stained with Hoechst, FeRhoNox-1, and Perls/DAB for CLEM experiments upon treatment with 1 mM FeSO₄ for 20 min c, Representative CLEM images of HEK293T cells following treatment with 1 mM ascorbate +1 mM FeSO₄ for 20 min. Micrographs (pink bordered) show high magnification of the indicated region. The yellow lines indicate structures of the endoplasmic reticulum (ER). Scale bars of light microscopy images represent 15 μm, 5 μm for low magnification, and 2 μm for high magnification EM images. Representative data were selected from n = 8–15 replicates. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)