Apolipoprotein-B (ApoB) is a protein, involved in the metabolism of lipids and is the main protein constituent of lipoproteins such as very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL). ApoB exists in the plasma in two main iso forms. ApoB100 and ApoB48. ApoB100 is synthesised in the liver, and is the major apolipoprotein of VLDL, intermediate density, and LDL, and is absolutely required for  their formation. ApoB100 acts as a ligand for LDL receptors in various cells throughout the body, allowing cells to internalise LDL and absorb cholesterol. ApoB48 is expressed in the intestine and is present on chylomicrons and their remnants lacking the C-terminal, LDL-receptor binding region of ApoB100. Elevated plasma concentrations of ApoB containing lipoproteins, are key risk factors for the development of atherosclerosis. Anti-Human ApoB is used for the detection of elevated levels of ApoB in the patient serum which may indicate the high risk of developing cardiac diseases. It also is used in the development and manufacturing of various qualitative and quantitative assays based on RID, IEP, ELISA, latex enhanced immunoturbidimetric assays, ouchterlony double diffusion, western blot, and precipitin assays.