Fig. 1. Double fluorescence microscopy of methanol/acetone-fixed AK13-1 cells to detect the distribution of the CK13-EGFP chimera HK13-EGFP (A-D) together with human CK5 using polyclonal rabbit antibodies (A'-D') before (A,A') during (B,B',C,C') and 50 minutes after a 10 minute treatment with 5 mM OV (D,D'). Note the progressive loss of CKFs during OV incubation accompanied by formation of granules throughout the cytoplasm, which remain in close association with residual filaments. Both processes are reversed upon removal of the drug, yielding a fine CKF cytoskeleton. Bars, 10 µm.