Listeria serogroup-specific antibody, IgG (serum/plasma)
This test measures your immune system’s response to *Listeria*, a bacteria that can cause serious infections, especially in pregnant people, newborns, older adults, or those with weakened immune systems.
["Checks if your body has developed antibodies against *Listeria* after exposure."]
Key facts at a glance
- LOINC
- 74732-9
- Short code
- Deprecated Listeria sp tuf Bld Pos Ql Prb Mag
- Synonyms
- Deprecated Listeria sp tuf Bld Pos Ql Prb Mag
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-mag-capture
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Listeria is a rare but dangerous foodborne illness. This test helps determine if you’ve been exposed to the bacteria by detecting antibodies your immune system produces in response. It’s not used to diagnose an active infection but can be part of monitoring for past exposure or assessing risk in certain groups (e.g., pregnant individuals or immunocompromised patients).
What It Measures
The test looks for *IgG antibodies*—a type of protein your immune system makes to fight off infections. These antibodies remain in your blood for years after exposure, so this test can indicate whether you’ve had prior contact with *Listeria*, even if you never developed symptoms.
Sample and Preparation
A blood sample is drawn from a vein in your arm. You may feel a slight pinch, but it’s quick and doesn’t require special preparation. No fasting is needed unless instructed by your healthcare provider.
When You Might Need This Test
Your doctor may recommend this test if you’re at higher risk for *Listeria* infection, such as during pregnancy, if you have a weakened immune system, or if you’ve had recent exposure to contaminated food (e.g., unpasteurized dairy, deli meats, or ready-to-eat foods). It’s also sometimes used in research or outbreak investigations.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Positive results suggest past exposure to *Listeria*, which may help guide preventive measures (e.g., avoiding high-risk foods) or rule out other infections. However, a positive test alone doesn’t confirm an active infection—additional testing or clinical symptoms are needed. This test is most useful in high-risk populations to assess exposure history or monitor immune response.
Short name
Listeria IgG Antibody
Frequently asked questions
What Does a Positive Result Mean?
Can This Test Detect an Active Infection?
How Long Do Antibodies Last After Exposure?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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