Expression and subcellular localization of the C-22 P0 epitope in colon adenocarcinoma cell lines (SW260 and HT29). Panel A The expression of the C-22 P0 epitope was determined by western blotting. The recombinant proteins GST-P0/P1/P2 were used as positive control. Panel B. Indirect immunofluorescence was performed using not fixed and not permeabilized SW260 and HT29 cells. Cell morphology was determined by phase-contrast microscopy. The antibody UPC 10 was used as a negative control.