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Immunoassay for Immunoglobulin G (IgG) Subclass 1 (IgG1) in Serum

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

This test measures the level of a specific type of antibody (IgG1) in your blood serum, which plays a key role in immune responses.

Quick summary

["IgG1 helps fight infections and is important for long-term immunity."]

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

Key facts at a glance

LOINC
33510-9
Short code
C immitis IgM Spec Ql IA
Synonyms
C immitis IgM Spec Ql IA
Category
chemistry
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

Why This Test Might Be Ordered

Your healthcare provider may order this test to evaluate immune function, diagnose or monitor conditions affecting antibody production, or assess responses to treatments like vaccines or medications that boost immunity.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into your arm to draw blood. If you’re on blood thinners, let your provider know beforehand.

What the Test Results Mean

Results help determine if your immune system is producing enough IgG1 antibodies, which could indicate normal function, deficiency, or an underlying issue requiring further investigation.

Common Conditions Monitored

This test is often used to monitor conditions like chronic infections, autoimmune diseases, or immune deficiencies, such as primary immunodeficiency disorders or after treatments like chemotherapy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: IgG1 levels can be low in people with immune system disorders, infections, or certain genetic conditions. High levels may suggest overactive immune responses or certain inflammatory conditions. Results are interpreted in context with your overall health and medical history.

Short name

IgG1 Subclass Test

Frequently asked questions

What does an abnormal IgG1 level mean?
An abnormal result may signal an immune issue, such as a deficiency in antibody production or an overactive immune response. Your provider will discuss findings with you and may recommend further testing or treatments.
How often should I get this test?
Frequency depends on your condition and treatment plan. Your healthcare provider will determine how often you need testing based on your specific needs and medical history.
Can lifestyle changes affect IgG1 levels?
While diet and lifestyle factors may influence overall immune function, IgG1 levels are primarily measured in blood and are not directly affected by daily habits unless a condition like malnutrition or chronic illness is present.
  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