||Maintaining body cholesterol homeostasis is critical for normal physiological functions and is achieved by a highly regulated balance of de novo synthesis, dietary cholesterol absorption, biliary clearance, and excretion. However, the mechanisms controlling cholesterol absorption are not well understood. A better understanding of the relationship between cholesterol absorption and synthesis may allow for the development of powerful novel strategies for the prevention and treatment of hypercholesterolemia. The Cholesterol Uptake Cell-Based Assay Kit provides a convenient tool for studying cholesterol absorption modulators. The kit employs NBD Cholesterol, a fluorescently-tagged cholesterol, as a probe for the detection of cholesterol taken up by cultured cells. U-18666A, a cholesterol intracellular trafficking inhibitor, is included as a positive control.