Fig. 3. The effect of Brefeldin A, Nocodazole and Cytochalasin D on Golgi, microtubules and actin filaments. Confluent monolayers of HeLa cells were fixed and stained with a primary antibody to ERGIC (p58) under control conditions (A) and following 5 hours treatment with 5 µg/ml BFA (B); microtubule integrity was monitored by use of antibodies to ß-tubulin under normal conditions (C) and following 5 hours treatment with 20 µg/ml nocodazole (D). The structural integrity of actin filaments was determined by staining with pholloidin before (E) and after 5 hours treatment with 1 µg/ml cytochalasin D (F). Bar, 10 µm.