Mycobacterium tuberculosis DNA, Plasma, Qualitative, Nucleic Acid Probe
This test looks for genetic material (DNA) from Mycobacterium tuberculosis, the bacterium that causes tuberculosis, in a plasma sample. A qualitative result simply indicates whether that DNA was detected.
["A positive result suggests tuberculosis DNA is present, but results must be interpreted together with symptoms, imaging, and other tests by a healthcare professional."]
Key facts at a glance
- LOINC
- 53257-2
- Short code
- M tb DNA # Spec NAA+probe
- Synonyms
- M tb DNA # Spec 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
What This Test Measures
The test uses a nucleic acid probe technique to detect DNA specific to the Mycobacterium tuberculosis complex in plasma. It is a qualitative method, meaning it reports whether the target DNA is found rather than measuring a quantity.
Why Plasma Is Used
Plasma is the liquid portion of blood after cells are removed. Testing plasma for tuberculosis DNA is less common than testing respiratory specimens such as sputum, but it may be used when blood-based or disseminated infection is being evaluated.
How the Sample Is Collected
A blood sample is drawn from a vein, usually in the arm, and collected in a tube that preserves plasma. The laboratory then separates the plasma and processes it for DNA detection.
Understanding Your Result
A "detected" result means tuberculosis DNA was found in the sample; "not detected" means it was not found. Neither result alone confirms or rules out active disease, so your clinician will combine it with your history, exam, and other testing.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Nucleic acid testing for Mycobacterium tuberculosis can support the diagnosis of tuberculosis, especially when rapid detection is needed. However, blood or plasma testing is not a standard replacement for sputum or tissue testing, and detection depends on the amount of bacteria present. False negatives can occur, and a positive result should prompt confirmatory evaluation and public health reporting as required.
Short name
M. tuberculosis NAAT (plasma)
Frequently asked questions
Does a "not detected" result mean I do not have tuberculosis?
Can this test tell me how severe my infection is?
Do I need to fast or prepare for this test?
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