Confocal microscopy identified several Zn transporters associated with the “secretory compartment” in mammary epithelial cells. Double-immunofluorescence imaging of Zip3 (green) illustrated co-localization (merge, yellow) with the mannose 6-phosphate receptor (M6PR, red) a late endosome marker. Zip7, Zip11, ZnT5, ZnT6 and ZnT10 (red) were partially co-localized (merge, yellow) with (p58, green) a trans-Golgi apparatus marker. ZnT8 (green) co-localized with calnexin (red) an endoplasmic reticulum marker M6PR (red) in mammary epithelial cells. Images were collected at 40X magnification.