Immunoglobulin G (IgG) Subclass Electrophoresis (Serum)
This test measures the levels of different subclasses of Immunoglobulin G (IgG), a key antibody protein in your blood. It helps identify which IgG subclasses may be low or high, which can inform treatment or management of certain immune-related conditions.
["IgG subclass electrophoresis helps diagnose and monitor immune system disorders by identifying imbalances in antibody types."]
Key facts at a glance
- LOINC
- 55922-9
- Short code
- IgG Ser Elph-mCnc
- Synonyms
- IgG Ser Elph-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- electrophoresis
- CPT
- 82784
- 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 Is This Test Done?
Your healthcare provider may order this test if you have symptoms of immune system issues, such as frequent infections, autoimmune diseases, or certain blood disorders. It may also be used to evaluate why certain treatments for immune-related conditions aren’t working as expected.
What Does the Test Measure?
The test uses electrophoresis to separate and analyze different IgG subclasses (IgG1, IgG2, IgG3, IgG4) in your serum. Each subclass has a distinct role in your immune response, and their levels can vary based on health conditions or treatments.
Sample Collection and Preparation
A blood sample is drawn from a vein, typically in your arm. The serum (the liquid part after blood clots) is then processed and sent to a lab for electrophoresis analysis. This process separates the IgG proteins by size and charge to identify their relative amounts.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to avoid certain medications or supplements that could affect test results. If you have a history of blood clotting issues or are on anticoagulants, let your provider know.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
IgG subclass electrophoresis
Frequently asked questions
Low levels of certain IgG subclasses may indicate weakened immune function, while high levels could suggest overactivity or specific immune disorders. For example, low IgG2 is linked to recurrent sinus or respiratory infections, while IgG4 elevations may be associated with certain autoimmune conditions or allergic reactions.
How long will results take?
What if my results are abnormal?
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