UIBC
Unsaturated Iron Binding Capacity
- Sample
- Blood
- Usual units
- µg/dL
Also known as Unsaturated Iron Binding Capacity · Unsaturated IBC
What this test measures
Unsaturated iron-binding capacity is the portion of blood's iron-carrying capacity that is not currently occupied by iron. It is the difference between total iron-binding capacity and the iron actually bound. A lab measures it alongside serum iron and TIBC — together the three describe how much iron is present and how much room the blood's carrier proteins still have for it. It is usually reported in micrograms per deciliter (µg/dL).
Reading your report
There isn’t one standard range for this test — each lab prints its own. Use the range shown next to your result.
Related guides
- Guide
Why the same blood test has different "normal" ranges at different labs
Reference intervals are built from each lab's own population and equipment, which is why two labs can print different ranges for the same sample.
- Guide
Reference interval, cutoff, and the "optimal" numbers online: three different things
The range beside your result, the target a website quotes, and the threshold that defines a condition are built in different ways and answer different questions.
- Guide
Why the same lab printed a different reference range for you this year
Ranges are not fixed constants. The lab can change method, revise its reference group, or apply a range that depends on your age — none of which is an error.
- Guide
Ferritin, serum iron, TIBC and transferrin saturation: four views of iron
An iron panel measures iron in circulation, iron in storage, and the capacity to carry it — plus a percentage computed from two of them.
- Guide
µ and μ are different characters, and lab software often disagrees about which one it used
Two visually identical characters sit behind the µ in µg/dL. Software treats them as different, which is why a unit can fail to match itself between two reports.