Thyroid hormone protein electrophoresis (serum/plasma)
This test measures the distribution of thyroid-related proteins in your blood, which can help assess how thyroid hormones are bound to proteins like thyroxine-binding globulin (TBG) and albumin.
["It helps evaluate thyroid function and potential binding abnormalities."]
Key facts at a glance
- LOINC
- 48073-1
- Short code
- T4BG Pnl SerPl Elph-mCnc
- Synonyms
- T4BG Pnl SerPl Elph-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 12
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- electrophoresis
- CPT
- 84436
- SNOMED
- 302345006
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms of thyroid dysfunction, such as fatigue, weight changes, or unexplained goiter (enlarged thyroid). It can also be used to monitor thyroid hormone levels in patients with known thyroid disorders or those taking thyroid medications.
What to Expect Before the Test
No special preparation is needed. You may have a small needle inserted into a vein in your arm, and blood will be drawn into a tube. This is usually done at a lab or your doctor’s office.
How the Test Results Are Interpreted
Results show the proportion of different thyroid-binding proteins in your serum or plasma. Abnormal patterns may indicate conditions like thyroid hormone resistance, genetic disorders affecting protein binding, or other metabolic issues.
Common Conditions Monitored
This test is less commonly used today but may be part of broader thyroid evaluations in rare cases where protein binding abnormalities are suspected, such as in hereditary thyroid dysalbuminemia.
Reference range
Adult: 4.5-12.0 μg/dLN/A
Take your thyroid medication after the blood draw if applicable. No fasting required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Thyroid protein electrophoresis can indirectly reflect how thyroid hormones circulate in your bloodstream. While not a direct measure of hormone levels, it helps identify potential imbalances in protein binding that could affect thyroid function or hormone availability for your body.
Short name
Thyroid protein electrophoresis
Frequently asked questions
What does a thyroid protein electrophoresis test measure exactly?
Is this test painful or uncomfortable?
Can fasting affect this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy