Cells were fixed with 4% paraformaldehyde for 15 minutes at room temperature and permeabilized with permeabilization buffer + 10% FBS in PBS for 10 minutes. Cells were incubated with ab91065 and goat anti-GM130 Golgi marker (ab1299) overnight at 4°C in the dark. Cells were washed once and stained with Alexa Fluor 647-conjugated donkey anti-rabbit IgG and Alexa Fluor 488-conjugated donkey anti-goat IgG secondary antibodies. DAPI - DNA. Dual-29 cells were used as a positive control, and the other cell samples were then evaluated at the same frequency. Overexpression of HS3st1 in Dual-29 cells resulted in a broad distribution of HS3st1. Overexpression of HS3st1 in Dual-10 cells localized HS3st1 in the Golgi. Overexpression of Golgi-targeted HS3st1 in CHO-gt31 localized HS3st1 in the Golgi.