Human neuronal cell viability demonstrated in culture after cryopreservation

A human neuronal cell freezing technique has been developed. The results indicate that human fetal neuronal cells can be frozen with 7%-10% dimethyl sulfoxide (DMSO) as cryoprotectant. The survival of isolated thawed cells has been evaluated in culture. Cells have been frozen at -196 degrees C for 370 days without loss of viability. Average recovery rate of frozen cells was 62% of the recovery rate of cultured unfrozen controls. Thawed cells show neurite outgrowth and maintain both cellular markers such as neuron specific enolase (NSE) and neurochemical characteristics (GABA synthesis). Morphological integrity of cryopreserved neurons has been confirmed at ultrastructural level.