Junctional staining of the colon cancer cell line Caco-2. Panels A-C. Confluent Caco-2 cells were co-immunostained with the polyclonal M-APC antibody and for microtubules. A microtubule-independent junctional localisation is seen. Tubulin green, APC red and DAPI blue. Panel C is a merged image. Panels D-F. Confluent Caco-2 cells immunostained using the monoclonal antibody ALI 12-28. Tubulin red, APC green and DAPI blue. Panel F is a merged image. Panels G-I. A monoclonal antibody specific for the APC C-terminus shows no specific APC localisation, as would be expected with the truncated APC expressed in Caco-2 cells. Tubulin red, APC green and DAPI blue, panel I is a merged image. Panels J-L. Actin and APC co-staining in Caco-2 cells confirms the localisation of APC to junctional membranes. Actin green, M-APC red, panel L is a merged image. Bars = 10 μm.