Mycobacterium tuberculosis antibody, serum/plasma (immunoassay) – qualitative
This test detects antibodies in your blood that may indicate past or potential exposure to *Mycobacterium tuberculosis*, the bacterium responsible for tuberculosis (TB). It helps assess whether your immune system has encountered this organism.
["This screening may guide decisions about further testing or preventive measures if TB exposure is suspected."]
Key facts at a glance
- LOINC
- 53702-7
- Short code
- M bovis - M avium tuberc IFN-g Bld-aCnc
- Synonyms
- M bovis - M avium tuberc IFN-g Bld-aCnc
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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
What This Test Measures
The test looks for specific antibodies produced by your immune system in response to *Mycobacterium tuberculosis*. These antibodies can appear after exposure, even if you don’t currently have active TB. The method used is an immunoassay, which detects these antibodies with high sensitivity.
Why It’s Done
Your healthcare provider may order this test if you have symptoms like coughing, fever, or weight loss, or if you live in an area with higher TB rates. It’s also used in screening for people at increased risk, such as those with weakened immune systems or recent travelers to TB-endemic regions.
What to Expect
No special preparation is needed. A blood sample is drawn from a vein, usually in your arm. The test result is qualitative (yes/no) rather than quantitative, meaning it only confirms the presence or absence of antibodies, not their exact level.
Possible Results and Next Steps
A positive result suggests past exposure or possible infection, but it doesn’t confirm active TB. You may need further testing, such as a TB skin test or chest X-ray, to determine if treatment is needed. A negative result means no detectable antibodies were found, but this doesn’t rule out past exposure.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily a screening tool. A positive result prompts further evaluation to rule out active TB or latent infection. It’s not used to diagnose active TB directly but can help identify individuals who may need additional diagnostic testing, such as sputum cultures or a TB skin test (like the Mantoux test).
Short name
TB Antibody Screen (Serum/Plasma)
Frequently asked questions
What does a positive result mean?
Can this test detect active TB?
How soon after exposure can I get a positive result?
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