Histochemical identification of guinea-pig macrophages by monoclonal antibody MR-1

A monoclonal antibody is described which reacts with monocytes and macrophages of the guinea-pig. The antibody recognizes a cytoplasmic component in the majority of tissue macrophages, as detected by histochemical analysis. It reacts positively with all macrophages in lymphoid organs, including Tingible body macrophages. In addition it recognizes the cells of Von Kupffer in the liver, and macrophages in bone marrow and peritoneal cavity. In comparison to other monoclonal antibodies that have been described in the guinea-pig, MR-1 shows a unique tissue distribution. The antibody is a useful tool to discriminate macrophages by immunohistochemical methods.