Transferrin, HRP. Transferrins (Tf) are an approximately 80kDa blood plasma glycoprotein synthesized by the liver. They are iron binding transport proteins which can bind two Fe(3+) ions in association with the binding of an anion, usually bicarbonate. It is responsible for the transport of iron from sites of absorption and heme degradation to those of storage and utilization. Transferrin is the primary blood iron transport protein and under normal conditions; approximately one-third of total blood transferrin contains bound iron. Measurement of blood transferrin levels can be used as an indicator for blood iron-carrying capacity and abnormalities of iron metabolism such as anaemia, iron overload and haemochromatosis. Serum transferrin may