Immunoglobulin G (IgG) Subclass Measurement by Electrophoresis
This test measures the levels of different subclasses of Immunoglobulin G (IgG), a key part of your immune system. IgG is the most common antibody in your blood and helps fight infections.
["IgG subclasses help identify immune system function and potential deficiencies."]
Key facts at a glance
- LOINC
- 110010-6
- Short code
- BLGG
- Synonyms
- B-Lactoglob IgG Msmt Ser
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 0.35
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme-Linked Immunosorbent Assay (ELISA) or Fluorescent Enzyme Immunoassay (FEIA) for quantitative detection of beta-lactoglobulin-specific IgG antibodies
- CPT
- 86001
- SNOMED
- 395131003
- Specimen volume
- 1.0 mL serum (minimum 0.5 mL)
- Stability
- Stable for 7 days at 2-8°C; for extended storage, freeze at -20°C or below for up to 3 months. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if you have symptoms like frequent infections, unexplained fatigue, or if they suspect an immune disorder. It can also be part of evaluating conditions like lupus, rheumatoid arthritis, or other autoimmune diseases.
What to Expect During the Test
You will likely have a simple blood draw from a vein in your arm. The blood sample is processed to separate serum, where the IgG subclasses are measured using electrophoresis, a technique that separates proteins based on size and charge.
Preparation for the Test
No special preparation is needed for this test. However, avoid eating or drinking anything (except water) for at least 8 hours before the blood draw if instructed by your provider.
What the Results Mean
Results show the concentration of each IgG subclass (IgG1, IgG2, IgG3, IgG4). Abnormal levels may indicate immune system issues, such as low IgG subclasses (which can make you more prone to infections) or high levels (which might be associated with certain autoimmune conditions).
Reference range
Negative: <0.35 kU/L; Equivocal: 0.35-0.70 kU/L; Positive: >0.70 kU/L. Reference ranges may vary by laboratory and assay manufacturer.N/A
No special preparation required. Patient should continue normal diet unless instructed otherwise. Recent consumption of dairy products does not typically interfere with IgG antibody testing.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
IgG subclass levels
Frequently asked questions
What causes IgG subclass levels to be checked?
How long does it take to get the results?
Can diet or lifestyle affect IgG subclass levels?
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 15, 2026. · Read our editorial policy