Fasting Required: No Specimen: Blood Results: 2-3 Business Days Description: Measures all of the proteins in the blood that are available to bind with iron, including transferrin. Since transferrin is the primary iron-binding protein, the TIBC test is a good indirect measurement of transferrin. The body produces transferrin in relationship to the need for iron. In healthy people, about one-third of the binding sites on transferrin are used to transport iron. Methodology Spectrophotometry (SP) Clinical Significance Serum iron quantification is useful in confirming the diagnosis of iron-deficiency anemia or hemochromatosis. The measurement of total iron binding in the same specimen may facilitate the clinician's ability to distinguish between low serum iron levels caused by iron deficiency from those related to inflammatory neoplastic disorders. The assay for iron measures the amount of iron which is bound to transferrin. The total iron binding capacity (TIBC) measures the amount of iron that would appear in blood if all the transferrin were saturated with iron. It is an indirect measurement of transferrin concentrations but expressed as an iron measurement. To obtain the percent saturation, the serum iron is divided by the TIBC which gives the actual amount of saturated transferrin. The percent saturation is low in iron deficiency and high in iron storage diseases.