Mycobacterium tuberculosis complex (MTB) complex antigen detection by immunoassay (qualitative)
This test checks for the presence of specific antigens linked to *Mycobacterium tuberculosis*, the bacterium responsible for tuberculosis (TB). It helps identify if TB is actively spreading in your body.
["A quick way to detect TB infection by detecting antigens in your blood or urine."]
Key facts at a glance
- LOINC
- 88874-3
- Short code
- M TB Cmplx DNA Islt/Spm Ql
- Synonyms
- M TB Cmplx DNA Islt/Spm Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- 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 if you have symptoms like persistent cough, fever, night sweats, or weight loss—especially if you’ve traveled to areas with higher TB rates or have been exposed to someone with TB. It’s also used in screening for people at higher risk, such as those with weakened immune systems or certain medical conditions.
How the Test Works
The test uses an immunoassay (a lab method that detects specific proteins) to identify antigens from *Mycobacterium tuberculosis* in your blood or urine. If TB is present, the test can detect these antigens, helping confirm infection before symptoms appear.
Sample Collection and Preparation
A blood sample or urine sample is collected and sent to a lab. The lab processes the sample to detect the TB antigens using sensitive immunoassay technology. Results are reported as either positive or negative.
What to Expect After the Test
If you receive a positive result, further testing (like a TB skin test or culture) will be needed to confirm the diagnosis and guide treatment. A negative result means no TB antigens were detected in this sample, but TB could still be present in other parts of your body.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive result strongly suggests active TB infection and is critical for early treatment. This test is particularly useful for rapid screening in high-risk populations, where traditional tests like cultures may take longer. However, it’s not a definitive diagnosis—additional tests are needed to confirm TB and guide treatment plans.
Short name
MTB Antigen Screen (Qualitative)
Frequently asked questions
How long does it take to get results from this test?
Can this test be used for everyone, or are there specific groups it’s recommended for?
What if my test comes back negative, but I still feel sick?
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