We isolated a cholesterol-enriched membrane subpopulation from the so-called lipid raft fractions of Jurkat T-cells by taking advantage of its selective binding to a cholesterol-binding probe, BCh. The BCh-bound mem-brane subpopulation has a much higher cholesterol⁄phospholipid (C⁄P) molar ratio ( ) than the BCh-unbound population in raft fractions ( ). It contains not only the raft markers GM1 and flotillin, but also some T-cell receptor (TCR) signalling molecules, including Lck, Fyn and LAT. .
