The total iron binding capacity (TIBC) – serum test is carried out along with other iron tests. This test helps to assess the ability of the body to transport iron in the blood. It helps in diagnosing iron deficiency and iron overload. The total iron binding capacity (TIBC) – serum test is done: • In case of low levels of hemoglobin and hematocrit on complete blood count • In case of signs and symptoms of iron deficiency • In case of sign and symptoms of iron overload