Glutathione utilization is highly spatiotemporal during embryonic development. Zebrafish embryos aged 24 (n = 16), 48 (n = 27), 72 (n = 29) and 96 (n = 27) hpf were stained with MCB and imaged. Values are mean + SEM fluorescence intensities normalized to the autofluorescence intensity of the specified structure in unstained embryos. Different letters indicate statistically significant differences (p ≤ 0.05), as determined by a one-way ANOVA followed by a Tukey-Kramer post-hoc. Right: Heatmaps of MCB fluorescence at the specified ages. For raw, unprocessed images and autofluorescence images, please refer to Supp. Fig. 1.