(A) The antibody titer was tested immunohistochemically using 1,000-times diluted sera of immunized mice as the first antibody on AMeX-fixed A549 cells, which were used as an immunogen. The sera of immunized mice contained antibodies that reacted with various cell components, such as the nucleus (↑), plasma membrane (▴), and cytoplasm (↑↑). (B) Immunoprecipitation with KU-Lu-5 antibody. Immunoblot analysis using KU-Lu-5 hybridoma supernatant as the first antibody [ lane 1: A549 lysate, lane 2: A549 lysate combined with protein G, lane 3: KU-Lu-5 antibody combined with protein G, lane 4: A549 lysate combined with KU-Lu-5 antibody]. Lanes 2 to 3 are negative controls, and immunoprecipitated product with KU-Lu-5 antibody was detected in lane 4 (↑). (C) Confirmation of identified antigen protein. KU-Lu-5 antibody reacted with recombinant CAXII protein (64 kDa), but not with recombinant Venus protein.