Microglia, resident phagocytic cells of the central nervous system, are frequent contaminants of astrocyte cultures. Unfortunately and not always fully appreciated, contamination by microglia can confound results of studies designed to elucidate the molecular mechanisms underlying astrocyte-specific responses. The paradigm described herein employs the mitotic inhibitor, cytosine β-d-arabinofuranoside, followed by the lysosomotropic agent, leucine methylester, to maximally deplete microglia, thereby generating highly enriched astrocyte monolayers that remain viable and functional. Successful removal of microglia from confluent monolayers of primary astrocyte cultures is achieved without the need for cell passage and successful reduction is confirmed by depletion of microglial-specific markers.