Mycobacterium tuberculosis DNA (Qualitative, Nucleic Acid Probe)
This test detects genetic material from *Mycobacterium tuberculosis*, the bacterium responsible for active tuberculosis (TB). It helps determine if you have an active TB infection by checking for the presence of TB bacteria in your sample.
A TB DNA test can help confirm or rule out active TB infection quickly, especially in cases where other tests may be inconclusive.
Key facts at a glance
- LOINC
- 103193-9
- Short code
- Mycobact ulcerans DNA Wnd Ql NAA+probe
- Synonyms
- Mycobact ulcerans DNA Wnd Ql NAA+probe
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- 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
How the Test Works
The test uses a specialized probe to identify specific DNA sequences unique to *M. tuberculosis*. This probe binds to the genetic material if the bacteria are present in your sample, allowing for a qualitative (yes/no) result. The method is highly sensitive and can detect very small amounts of TB DNA.
What the Test Measures
The test measures the presence or absence of *Mycobacterium tuberculosis* DNA in your sample. It does not measure the amount of bacteria but confirms whether the genetic material is present, which can indicate an active infection.
When You Might Need This Test
You may need this test if you have symptoms of TB (such as coughing, fever, or weight loss), have been exposed to TB, or if your healthcare provider suspects TB after other tests. It is often used in screening, monitoring, or diagnosing active TB in certain clinical settings.
Sample Collection and Preparation
The test typically uses a sample of **sputum** (phlegm coughed up from the lungs) or, in some cases, other respiratory secretions. Your healthcare provider will guide you on how to collect the sample properly. The test does not require fasting or special preparation beyond providing the sample.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test plays a critical role in diagnosing active TB, especially in situations where traditional culture methods take longer. A positive result strongly suggests an active TB infection and may prompt immediate treatment. A negative result can help rule out TB, but further testing may still be needed depending on your symptoms and medical history. It is also useful for monitoring treatment response in patients undergoing TB therapy.
Short name
TB DNA Probe (Qualitative)
Frequently asked questions
What Does a Positive Result Mean?
What Does a Negative Result Mean?
How Long Does It Take to Get Results?
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