Macrophages are cells differentiated from circulating bone marrow-derived monocytes. The main function of macrophages is to remove cellular debris and destroy invading pathogens. Rat Splenic Macrophages (RSMa) reside in the spleen and play a critical role in maintaining blood homeostasis. There are three distinct populations of splenic macrophages including: red pulp macrophages, marginal zone macrophages, and marginal zone metallophillic macrophages. RSMa perform iron processing functions and aid in the capture of microbes and viruses in the circulatory system. Recent studies have shown that splenic macrophages contribute to stroke pathology and autoimmune diseases. RSMa are an excellent model for studying macrophage functions under normal physiological and pathological conditions. RSMa from ScienCell Research Laboratories are isolated from adult rat spleen. RSMa are cryopreserved at P0 and delivered frozen. Each vial contains > 1 x 106 cells in 1 ml volume. RSMa are characterized by immunofluorescence with antibody to F4/80. RSMa are negative for mycoplasma, bacteria, yeast, and fungi. RSMa are guaranteed to further culture in the conditions provided by ScienCell Research Laboratories; however, RSMa are not recommended for expanding or long-term cultures since the cells do not proliferate in regular culture. Recommended Medium It is recommended to use Macrophage Medium (MaM, Cat. #1921) for culturing RSMa in vitro.