Light micrograph (LM) of Kupffer cells (sinusoid lining cells)of the liver. Also known as Browicz-Kupffer cells, Kupffer cells are specialized macrophages located in the liver lining the walls of the sinusoids that form part of the reticuloendothelial system (RES) (aka: mononuclear phagocyte system). This tissue was stained with a particulate iron-sugar compound, making the Kupffer cells appear blue. Magnification unknown.