C-12 NBD Cholesterol is a fluorescently-tagged cholesterol with the hydrophilic NBD fluorophore attached to the hydrophilic end of cholesterol, separated by a 12-carbon spacer. This allows the cholesterol to orient in membrane bilayers while the fluorescent tag is presented outside the bilayer. Fluorescently-tagged lipids have been used to study their interactions with proteins, utilization by cells and liposomes, and development of assays for lipid metabolism.
