Immunofluorescence Analysis of Cultured Mammalian Cell Nucleus Using Four Monoclonal Antibodies against the Nucleus

Abstract Four monoclonal antibodies recognizing antigenic determinants on the nuclei of cultured mammalian cells were isolated. Immunofluorescence studies using these antibodies demonstrated three immunofluorescence patterns of the nucleus; fluorescence staining on the nuclear envelope (antibody 266), on the nucleus (antibody 182, 261) and on both the nucleus and nuclear envelope during the cell cycle (antibody 108). Antibody 108 stained cytoplasmic vesicles of interphase cells. When using mitotic chromosomes, antibody 108 reacted with the perichromosomal region, while antibodies 182 and 261 stained intrachromosomal substance. Immunoblot analysis showed that monoclonal antibody 108 recognized a protein of molecular weight 40K in both the cytoplasm and the perichromosomal region. The molecular weight of the antigen which reacted with antibody 182 was 37K