Transferrin
Serum Transferrin
- Sample
- Blood
- Usual units
- mg/dL
Also known as Serum Transferrin · Siderophilin
What this test measures
Transferrin is a protein made mainly by the liver that carries iron through the bloodstream from where it is absorbed or released to where it is used. A blood test measures its concentration directly, complementing calculated measures like binding capacity that describe the same carrying function indirectly. It is usually reported in milligrams per deciliter (mg/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.