GOTO cells, a neuroblastoma cell line retaining the ability to differentiate into neuronal or Schwann cells, were found to be rich in membrane rafts containing ganglioside GM2 and hypersensitive to lipid raft-disrupting methyl-beta-cyclodextrin (M beta CD); the GM2-rich rafts and sensitivity to M beta CD were markedly diminished upon their differentiation into Schwann cells. We first raised a monoclonal antibody that specifically binds to GOTO cells but not to differentiated Schwann cells and determined its target antigen as ganglioside GM2, which was shown to be highly concentrated in lipid rafts by its colocalization with flotillin, a marker protein of rafts. Disturbance of normal structure of the lipid raft by depleting its major constituent, cholesterol, with M beta CD resulted in acute apoptotic cell death of GOTO cells, but little effects were seen on differentiated Schwann cells. Until this study, GM2-rich rafts are poorly characterized and MbCD hypersensitivity, which may have clinical implications, has not been reported. (C) 2009 Elsevier Inc. All rights reserved.