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Cytomegalovirus (CMV) IgG Antibody, Serum (Qualitative)

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

This test checks for the presence of antibodies to the cytomegalovirus (CMV), a common virus that can affect the immune system. Antibodies indicate past or current infection.

Quick summary

["This test helps determine if you’ve been exposed to CMV, which can inform vaccination decisions or monitoring for immune-related conditions."]

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

Key facts at a glance

LOINC
45326-6
Short code
CMV IgG Avidity SerPl-Rto
Synonyms
CMV IgG Avidity SerPl-Rto
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?

The CMV IgG antibody test detects specific proteins (antibodies) your immune system produces in response to past or ongoing CMV infection. These antibodies are produced by your body to fight the virus. If antibodies are found, it suggests you have been exposed to CMV at some point.

Why Might Your Doctor Order This Test?

Your doctor may recommend this test if you have a weakened immune system (e.g., due to HIV, chemotherapy, or organ transplant), are pregnant (to assess risk to the baby), or have symptoms like fever, fatigue, or organ-related issues that could be linked to CMV.

What Does a Positive or Negative Result Mean?

A positive result means your body has produced antibodies to CMV, indicating past exposure. A negative result suggests you either have never been exposed or your immune system has cleared the virus. This does not confirm active infection without additional testing.

Sample Collection and Preparation

A blood sample is drawn from a vein in your arm. The sample is sent to a lab for testing. You may experience slight discomfort, but it usually lasts a few minutes. No special preparation is needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CMV IgG Antibody

Frequently asked questions

How often should I get this test?
The frequency depends on your health status. If you have a chronic condition (e.g., HIV, transplant), your doctor may recommend periodic testing. Pregnant individuals may need this test once during pregnancy. Always follow your healthcare provider’s guidance.
What are the possible side effects of this test?
Most people experience minimal or no side effects. Rarely, you might feel mild bruising, pain, or swelling at the injection site. If you experience severe pain, bleeding, or signs of infection (e.g., fever, redness), contact your doctor.
Can I drink or eat before this test?
No special diet or fasting is required for this test. However, always follow your doctor’s instructions for any pre-test preparations related to your overall health or medications.
  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