Apolipoprotein B (Apo B) is the major structural and functional protein component of low-density lipoprotein (LDL). Apolipoprotein B FS determines the Apo B concentration in serum and plasma. Elevated Apo B levels are strongly associated with coronary heart disease (CHD). Studies showed that especially the Apo B/Apo A1 ratio is a strong predictor for CHD.