Test Overview
Test Methodology

Immunoturbidimetric Assay

Test Usage

The evaluation of suspected iron-deficiency in patients who may have inflammation, infection, or chronic disease and other conditions in which ferritin concentration does not correlate with iron status, and also used in the evaluation of insulin-dependent diabetics for iron-deficiency resulting from gastric autoimmunity and atrophic gastritis.

Reference Range *

1.8 - 4.6 mg/L

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

The sTfR immunoassay should not be used for the routine clinical evaluation of patients for iron status when ferritin immunoassay would be appropriate, such as in the absence of confounding pathologies (inflammation, infection, chronic disease, or malignancy). Patients with hemolysis and recent blood loss may have falsely elevated sTfR levels. sTfR is elevated in patients with thalassemia and sickle cell disease. Caution should be exercised in managing anemia in these individuals based on sTfR test results.

Test Details
Days Set Up
Analytic Time

2 - 4 days

Soft Order Code
MiChart Code
Soluble Transferrin Receptor (sTfR)
  • STFR
  • Soluble Transferrin Receptor
Reference Laboratory
Mayo STFR (84283)
Special Testing
Specimen Requirements
Collection Instructions

Collect specimen in an SST or Red top tube. Centrifuge, aliquot serum into a plastic vial and freeze within 2 hours.

Yellow Top Tube
Normal Volume
1 mL serum
Minimum Volume
0.25 mL serum
Additional Information

Test sent to Mayo Medical Laboratories.

CPT Code
Fee Code