Isolation of Microglia Subpopulations

We describe a technique to isolate two major phenotypically different populations of microglia (type I and type II) in mixed brain culture. Type I microglia have surface markers for mature monocytic cells and produce microglia-specific cytokines. Type II microglia have cell-surface characteristics exclusively observed in immature bone marrow cells but not in mature monocytic cells, and do not express the hallmarks of mature microglia such as C3b receptors, CD14, or cytokine mRNAs.