High-density lipoprotein (HDL) consists of a protein shell, containing apolipoproteins A-I and A-II, and a hydrophobic core consisting of cholesterol and triglycerides surrounded by phospholipids and cholesterol esters. HDL transports cholesterol to the liver or steroidogenic organs such as adrenals, ovary, and testes by both direct and indirect pathways. HDL-Cholesterol is removed by HDL receptors such as scavenger receptor BI (SR-BI), which mediate the selective uptake of cholesterol from HDL. Clinically, high levels of HDL has been associated with cardiovascular health. This is due to the ability of HDL particle to transport cholesterol from lipid-laden macrophages of atherosclerotic arteries to the liver for secretion into the bile by a process called as reverse cholesterol transport. BioVision’s HDL Uptake Assay Kit contains a fluorescently-labeled HDL that can be measured when taken up by cells. Unlabeled-HDL is included in the kit for assay validation.