Skip to content

Total IgG Antibody Concentration (Serum)

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

This test measures the amount of Immunoglobulin G (IgG), a type of antibody in your blood. IgG helps fight infections and is the most common antibody in the body.

Quick summary

["IgG antibodies protect against infections and play a key role in long-term immunity."]

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

Key facts at a glance

LOINC
63133-3
Short code
Goat Milk IgG-mCnc
Synonyms
Goat Milk IgG-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 by your immune cells in response to infections, vaccines, or other triggers. This test helps doctors assess your immune response or check for conditions affecting antibody production.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms of a weakened immune system, such as frequent infections, or if you’re being treated for conditions like lupus, rheumatoid arthritis, or certain autoimmune diseases. It can also be used to monitor immune responses after vaccination or during pregnancy.

Sample Collection and Preparation

A blood sample is drawn from a vein in your arm. The blood is processed to separate the serum (the liquid part without blood cells), which is then tested for IgG antibodies using a specialized laboratory method.

What Are Possible Results?

Results are typically reported as a mass concentration (e.g., grams per liter). While reference ranges can vary by lab, lower than expected levels may suggest immune deficiencies, while higher levels could indicate chronic infections, certain cancers, or other conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG Antibody Level

Frequently asked questions

How long does it take to get my test results?
Test results are usually available within 1 to 3 business days, depending on your lab’s processing schedule. Your healthcare provider will contact you once the results are ready.
Can I eat or drink before this test?
You can eat and drink normally before this test, as it’s a blood draw and doesn’t require fasting. However, always follow any specific instructions your doctor gives you.
What if my IgG levels are abnormal?
If your IgG levels are lower than expected, your doctor may recommend further testing or treatments to address potential immune deficiencies. If levels are higher, they could be due to chronic illness or other underlying conditions that need evaluation.
  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