Total plasma protein content is 6–8 g/dL of which albumin is 3.5-5 g/dL and the rest is globulin. Almost all plasma proteins are synthesized in the liver except immunoglobulins. On agar gel electrophoresis albumin has maximum mobility while gamma globulin has minimum mobility. In chronic infection, gamma globulins are increased smoothly, while in paraproteinemias, M band is seen. The alpha 2 fraction is increased in nephrotic syndrome while albumin is decreased in liver cirrhosis, malnutrition, nephrotic syndrome. Albumin contributes to colloid osmotic pressure of plasma, has buffering capacity and is a transport medium for various hydrophobic substances. Hyper gamma globulinemia is seen in conditions of hypoalbuminemia, chronic infection and para proteinemias. The transport proteins in blood are albumin, pre-albumin (transthyretin), RBP, TBG, transcortin and haptoglobin. Polymorphism is when the protein exists in different phenotypes in the population, but only one form is seen in a particular person. This is seen in haptoglobin, transferrin, ceruloplasmin, alpha1 antitrypsin and immunoglobulins. The levels of certain proteins in blood may increase 50 –100 fold in various inflammatory and neoplastic conditions. Such proteins are called acute phase proteins, e.g. CRP, ceruloplasmin, haptoglobins, alpha1 acid glycoprotein, alpha1 antitrypsin and fibrinogen. Proteins that are decreased in blood during inflammatory response are called Negative acute phase proteins, e.g. albumin, transthyretin, and transferrin.