Total iron binding capacity

Total iron binding capacity (TIBC) is indirect measurement of transferrin receptors in blood. It is one one of the tests used in the differential diagnosis of anemia, the other major biochemical measurements being serum iron (SI), and serum ferritin. While the test is in widespread use, direct transferrin receptor measurement tests are becoming available for clinical practice.

Method

TIBC is calculated as the sum of unsaturated iron binding capacity (UIBC) and serum iron. Unsaturated iron binding capacity is directly measured by adding a known amount of iron to serum, and measuring the amount of iron that does not bind to transferrin receptors.