Zinc-induced fluorescence response in HeLa cells expressing AGT in the mitochondria (a-d) and in the Golgi apparatus (e-h). For each series, from the left: (i) DIC image, (ii) labeling with ZP1BG (10 μM, 1 h), (iii) addition of Zn(II)/pyrithione (1:1, 50 μM, 5 min), and (iv) subsequent addition of TPEN (100 μM, 5 min). Scale bar: 25 μm. See Figure S7 for full-view images.