Apolipoprotein is the protein associated with the largest component for High-Density Lipoprotein (HDL). The Apolipoprotein A1 represents about 45% molecular mass approximately. It aids in the reverse processing of the cholesterol from tissue to the liver. The test evaluates the survival rate or risk involved in heart patients and peripheral vascular diseases. Apo plays the most important role in the lipoprotein metabolism like transportation of hydrophobic molecules that are present in the plasma aqueous medium, cell surface and binding specific receptors correctly direct lipids along with targeting the organs as well as body tissues. acts as co-factor to the enzyme lecithin-cholesterol acyltransferase along with the cholesterol from cells.