Cryopreservation of rat astrocytes from primary cultures

Summary A deep-freezing procedure that makes possible a reproducible recovery of astrocytes for subsequent culture, after several months of cryopreservation, is described. The use of undiluted fetal bovine serum containing 10% dimethyl sulfoxide resulted in very high cell viability and survival. A simple and easy three-step (2 h at –20° C, 4 h at –70° C and storage in liquid N₂ at –196° C) cooling procedure has been shown to be adequate to yield very high cell viabilities. Cell viability, after a freezing-thawing cycle was about 94 to 97%, comparable to that of the astrocyte suspension obtained from the primary culture before freezing (95 to 100%). Three well-accepted markers of the astrocyte differentiation were examined in 7-day astrocytes, both primary cultured and cultured after thawing: glial fibrillary acidic protein, and the glutamine synthetase, and buthyl-cholinesterase activities.