Anti-IgG Immunoglobulin G Antibody (Serum) - Immunoassay
This test measures the presence of antibodies against the IgG immunoglobulin class in your blood serum. These antibodies may indicate past or current immune system exposure to certain infections or conditions.
["This test helps assess immune responses and diagnose or monitor conditions related to autoimmune diseases or infections."]
Key facts at a glance
- LOINC
- 19727-7
- Short code
- ASPNGRG
- Synonyms
- A niger IgG Ser Ql
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube (no anticoagulant)
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme-linked immunosorbent assay (ELISA) or Immunofluorescence assay (IFA) for detection of Aspergillus niger-specific IgG antibodies
- CPT
- 86606
- SNOMED
- 122088008
- Specimen volume
- 1–2 mL serum (minimum 0.5 mL)
- Stability
- Serum stable at room temperature for 8 hours; refrigerated (2–8°C) for 7 days; frozen (-20°C or below) for up to 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 200
- Icterus max
- 40
- TAT
- 48–168 hours
- Order
- routine
What This Test Measures
The test detects IgG antibodies, a type of protein produced by your immune system in response to infections, vaccines, or autoimmune conditions. IgG antibodies are the most common type of antibody in your blood and provide long-term immunity.
Why It’s Ordered
Your healthcare provider may order this test to diagnose or monitor conditions such as autoimmune diseases (e.g., lupus, rheumatoid arthritis), infections (e.g., hepatitis, HIV), or to evaluate immune responses after vaccination.
Sample Collection and Preparation
A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum, which is then tested for IgG antibodies using an immunoassay method.
What to Expect Before the Test
No special preparation is needed, but inform your provider if you are on blood-thinning medications or have a history of bleeding disorders. Avoid alcohol for 24 hours before testing if instructed.
Reference range
Negative: <1:160 titer; Equivocal: 1:160–1:320; Positive: >1:320. Reference values vary by laboratory and assay methodology; results interpreted in clinical context.N/A
No special patient preparation required. Fasting is not necessary. Patients should inform their healthcare provider of any immunosuppressive conditions, recent antifungal therapy, or exposure history that may affect results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
IgG Antibody Test
Frequently asked questions
What does an elevated IgG antibody level mean?
What does an abnormal IgG result indicate?
Can IgG antibody tests be used to diagnose infections?
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