TMEM119, is a plasma membrane protein first identified because of its role in the differentiation of osteoblasts (Kanamoto et al., 2009). However TMEM119 is also known to be a specific marker of microglia, the tissue-resident macrophages of brain and spinal cord (Bennett et al., 2016). Unlike other microglia markers, TMEM119 expression readily distinguishes resident microglia from blood-derived macrophages, making it a highly specific microglia marker. In healthy brain microglia are the resident immune cells where they act to neutralize pathogens, clear dead and dying cells, and prune synaptic connections. However, in neurodegenerative disease microglia can actually promote neuronal degeneration through reduced phagocytic clearance and increased pro-inflammatory effects. Our anti-TMEM119 antibody is a highly specific microglial marker for mouse TMEM119 and works by western blot and immunocytochemistry.