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Serum/plasma mass concentration of immunoglobulin G (IgG) by nephelometry

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

This test measures the amount of Immunoglobulin G (IgG), a type of antibody in your blood, using a specialized lab technique called nephelometry.

Quick summary

["IgG helps protect your body from infections and supports long-term immunity."]

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

Key facts at a glance

LOINC
47513-7
Short code
T palldm IgG Ser Donr Ql
Synonyms
T palldm IgG Ser Donr Ql
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

Why This Test Might Be Ordered

Your healthcare provider may recommend this test to check for low or high levels of IgG, which can occur in conditions like immune deficiencies, chronic infections, or certain autoimmune diseases. It may also be used to monitor treatment responses in patients receiving immunoglobulin therapy.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample, which usually causes only a brief pinch. If you’re on blood thinners, let your provider know before the test.

What to Expect During the Test

The blood sample is sent to a lab where it is analyzed using nephelometry, a method that measures how particles scatter light to determine IgG concentration. Results are typically available within 24–48 hours.

Possible Results and Next Steps

If your IgG levels are outside the expected range, your provider will discuss what this might mean for your health and may recommend further testing or adjustments to your treatment plan.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG Level

Frequently asked questions

What does a low IgG level mean?
Low IgG levels may indicate a weakened immune system, potentially due to conditions like primary immunodeficiency, chronic liver disease, or certain cancers. It can also be seen in patients who have had recent infections or are malnourished.
What does a high IgG level mean?
High IgG levels can sometimes be normal, especially in response to infections or vaccinations. However, they may also be seen in chronic inflammatory conditions, autoimmune diseases, or in patients receiving long-term immunoglobulin therapy.
How often should I get this test?
The frequency of this test depends on your medical condition and treatment plan. Your healthcare provider will determine how often you need monitoring, such as every few months or annually, based on your individual needs.
  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