Cholesteryl esters consist of a fatty acid esterified to the 3β-hydroxyl group of cholesterol. These very nonpolar species are the predominant lipid components of atherosclerosis plaque and low- and high-density lipoporotein (LDL and HDL) cores. The orange-red fluorescent BODIPY™ 542/563 cholesteryl ester can be used as a tracer of cholesterol transport and rand as a general nonexchangeable membrane marker.