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Antibody to Cytomegalovirus (CMV) IgG, Serum or Plasma

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

This test measures the presence of Immunoglobulin G (IgG) antibodies against the cytomegalovirus (CMV), a common virus that can affect the immune system.

Quick summary

["IgG antibodies indicate past or long-term exposure to CMV."]

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

Key facts at a glance

LOINC
60541-0
Short code
CMV EA Ag Spec Ql
Synonyms
CMV EA Ag Spec Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 This Test Measures

IgG antibodies are a type of protein produced by your immune system in response to an infection. If you have CMV IgG antibodies, it suggests you have been exposed to CMV at some point in your life, either through infection or vaccination (if applicable). These antibodies remain in your blood for a long time, helping your body fight off future infections.

Why It’s Done

Doctors may order this test to check for past CMV infection, especially in people who are at higher risk of complications, such as those with weakened immune systems (e.g., due to HIV/AIDS, chemotherapy, or organ transplant). It can also help monitor immune function in certain conditions.

When to Expect Results

Results are typically available within 1 to 3 business days, depending on your lab. Your healthcare provider will discuss the results with you and explain what they mean for your health.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into your arm or vein to draw a blood sample. If you have a blood disorder or are on blood thinners, let your doctor know before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A positive CMV IgG test indicates past infection, which is generally harmless but important to know if you have a compromised immune system. It does not show whether you currently have an active infection. In high-risk patients, this test helps assess immunity and guide treatment decisions.

Short name

CMV IgG Antibody

Frequently asked questions

How long does it take to get results from this test?
Results are usually ready within 1 to 3 days after the lab processes your sample. Your healthcare provider will share the results with you during your follow-up visit.
Can I have a false-positive result?
False positives are rare, but possible. If you have concerns, discuss your medical history with your doctor. They may recommend retesting if needed.
Does this test detect active CMV infection?
No, this test only detects IgG antibodies, which indicate past exposure. For active infection, your doctor may order additional tests, such as a CMV viral load or PCR test.
  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