Skip to content

Total IgG Antibody Level (Serum)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of Immunoglobulin G (IgG) antibodies in your blood serum. IgG is the most common type of antibody in the body and plays a key role in long-term immunity.

Quick summary

["IgG antibodies help protect your body from infections and diseases over time."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
47336-3
Short code
Deprecated S pneum22 IgG sp1 Ser IA-mCnc
Synonyms
Deprecated S pneum22 IgG sp1 Ser IA-mCnc
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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

What Does This Test Measure?

IgG antibodies are part of your immune system’s defense. They are produced in response to infections, vaccines, or exposure to foreign substances (antigens). This test helps assess your overall immune response by measuring the concentration of IgG in your blood.

Why Might You Need This Test?

Doctors may order this test to evaluate immune function, diagnose conditions like immunodeficiency, monitor treatment responses (e.g., for autoimmune diseases or infections), or check for antibody production after vaccination.

Common Uses and Indications

Common reasons include evaluating immune status in people with chronic illnesses, assessing antibody levels in newborns or immunocompromised patients, or confirming immune response to vaccines (e.g., COVID-19, flu).

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the blood draw if your doctor specifies it. Wear a comfortable shirt with an easy neckline for the procedure.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test helps doctors understand your immune system’s ability to produce antibodies, which can guide treatment decisions for infections, autoimmune diseases, or immune deficiencies.

Short name

IgG Antibody Test

Frequently asked questions

How is this test different from other antibody tests?
Unlike tests for specific antibodies (e.g., to a virus or disease), this test measures total IgG levels, giving a broad view of your immune antibody production across many pathogens.
What does a low or high IgG level mean?
Low IgG levels may indicate a weakened immune system, while high levels could suggest chronic infections, autoimmune responses, or certain medical conditions. Your doctor will interpret results in context with your health history.
Does this test detect recent infections?
No, this test measures IgG antibodies produced over weeks to months, so it reflects past exposure or vaccination—not recent illness.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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