Astrocytes are the majority cell type of the mammalian brain. Astrocytes have been implicated in a variety of supportive functions for their partner neurons in the CNS, such as neuronal guidance during development, and nutritional and metabolic support throughout life [1]. The functions of astroyctes are also complicated during pathological processes [2]. Numerous studies have demonstrated that astrocytes are among the most functionally diverse group of cells in the CNS [3]. Much of what we have learned about astrocytes is from in vitrostudies and astrocytes culture is continually providing a useful tool in exploring the diverse property of astrocytes. RA are isolated from day 2 rat cerebral cortex. RA are cryopreserved at secondary culture and delivered frozen. Each vial contains >1 x 10^6 cells in 1 ml volume. RA are characterized by immunofluorescent method with antibody to GFAP. RA are negative for mycoplasma, bacteria, yeast and fungi. RA are guaranteed to further expand for 5 population doublings in the condition provided by Creative Bioarray.