Learn more about...

Also Known As
Iron Binding Capacity
IBC
Serum Iron-Binding Capacity
Siderophilin
TIBC
UIBC
Formal Name
Transferrin, Total Iron Binding Capacity; Unsaturated Iron Binding Capacity; Transferrin Saturation
This article was last reviewed on
This article was last modified on August 6, 2018.
At a Glance
Why Get Tested?

Along with other iron tests, to assess your body's ability to transport iron in the blood; to help diagnose iron-deficiency or iron overload

When To Get Tested?

When you have low hemoglobin and hematocrit on a complete blood count (CBC); when your healthcare practitioner suspects you may have too much iron (overload) or too little iron (deficiency) in the body

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?

You may be instructed to have your blood drawn in the morning and/or fast for 12 hours before the test; in this case, only water is allowed. Follow any instructions from your healthcare practitioner and/or from the laboratory performing the test.

You may be able to find your test results on your laboratory's website or patient portal. However, you are currently at Lab Tests Online. You may have been directed here by your lab's website in order to provide you with background information about the test(s) you had performed. You will need to return to your lab's website or portal, or contact your healthcare practitioner in order to obtain your test results.

Lab Tests Online is an award-winning patient education website offering information on laboratory tests. The content on the site, which has been reviewed by laboratory scientists and other medical professionals, provides general explanations of what results might mean for each test listed on the site, such as what a high or low value might suggest to your healthcare practitioner about your health or medical condition.

The reference ranges for your tests can be found on your laboratory report. They are typically found to the right of your results.

If you do not have your lab report, consult your healthcare provider or the laboratory that performed the test(s) to obtain the reference range.

Laboratory test results are not meaningful by themselves. Their meaning comes from comparison to reference ranges. Reference ranges are the values expected for a healthy person. They are sometimes called "normal" values. By comparing your test results with reference values, you and your healthcare provider can see if any of your test results fall outside the range of expected values. Values that are outside expected ranges can provide clues to help identify possible conditions or diseases.

While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents, and techniques. This is a reason why so few reference ranges are provided on this site. It is important to know that you must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."

For more information, please read the article Reference Ranges and What They Mean.

What is being tested?

Transferrin is the main protein in the blood that binds to iron and transports it throughout the body. A transferrin test directly measures the level in the blood. Alternatively, transferrin may be measured indirectly (or converted by calculation) so that its level is expressed as the amount of iron it is capable of binding. This is called the total iron binding capacity (TIBC).

Iron is an essential nutrient that, among other...

Accordion Title
Common Questions
View Sources

Ask a Laboratory Scientist

 

Your questions will be answered by a laboratory scientist as part of a voluntary service provided by one of our partners, the American Society for Clinical Laboratory Science (ASCLS). Click on the Contact a Scientist button below to be re-directed to the ASCLS site to complete a request form. If your question relates to this web site and not to a specific lab test, please submit it via our Contact Us page instead. Thank you.

Contact a Scientist