Home
HelpTest Code TSI Thyroid-Stimulating Immunoglobulin, Serum
Test Down Notes
This test is temporarily unavailable. For additional details, see test update here.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumOrdering Guidance
This test is used for second-order testing for autoimmune thyroid disease.
For suspected cases of autoimmune hypothyroidism, the first-order testing is TPO / Thyroperoxidase Antibodies, Serum.
For suspected cases of autoimmune thyroid disease, first-order testing includes TPO and THYRO / Thyrotropin Receptor Antibody, Serum.
Specimen Required
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 60 days | |
| Refrigerated | 7 days | ||
| Ambient | 24 hours |
Reference Values
≤1.3 TSI index
Reference values apply to all ages.
Day(s) Performed
Monday through Friday
CPT Code Information
84445
Report Available
2 to 6 daysReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Name
Recombinant Bioassay
Forms
If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.