APC remains associated with IF proteins following extraction of actin and tubulin. (A) Left two panels, 184A1 epithelial cells analyzed by immunofluorescence microscopy reveal distribution of APC, lamin B1, keratin, tubulin, actin (detected with phalloidin) and DNA (blue in DIC overlay). Right two panels, following sequential extraction, APC remained cell associated, along with IF proteins lamin B1 and keratin. Note that actin, tubulin, and DNA were successfully extracted from these cells. Nuclei are indicated by DAPI staining. (B) Colocalization of APC (green) with keratins (red) after cell extraction. Scale bars, 10 μm.