2021 May 9. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–.
Total iron-binding capacity (TIBC) is an essential test used for the diagnosis of iron deficiency anemias and other disorders of iron metabolism. Iron binding capacity is the capacity of transferrin to bind with iron. Iron binding capacity is of two types, TIBC and unsaturated iron-binding capacity (UIBC). When iron stores are depleted, the transferrin levels increase in blood. As only one-third of transferrin is saturated with iron, so the transferrin present in serum has the extra binding capacity (67%). This is unsaturated iron-binding capacity. TIBC is the total of serum iron and UIBC. Percentage transferrin saturation is calculated by dividing serum iron by TIBC and multiplying the result by 100.