Rab6-GTP is detected by immunocytochemistry using anti-Rab6-GTP, mAb (AA2). Method: HeLa cells are grown in standard culture conditions, fixed with paraformaldehyde (3%), permeablized in PBS+ BSA 0.2 % + Saponin 0.05 % and incubated with anti-Rab6-GTP, mAb (AA2) (1μg /ml) in PBS-BSA-Saponin. After incubation for 30 min at RT and several washes in PBS, cells are treated with a goat anti-human (Cy3) antibody in PBS-BSA-Saponin for 30 min at RT, washed and mounted in Moewiol. Nuclei are stained with DAPI.