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Mycobacterium tuberculosis complex (MTBC) nucleic acid detection by probe-based molecular assay (whole blood)

Published: August 9, 2026Updated: August 16, 2026

This test checks for genetic material from *Mycobacterium tuberculosis*, the bacteria responsible for tuberculosis (TB). It helps determine if you may have an active TB infection.

Quick summary

["A molecular test for TB bacteria in your blood, used to confirm infection before symptoms appear."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
38379-4
Short code
M TB Cmplx DNA Spec Ql NAA+probe
Synonyms
M TB Cmplx DNA Spec 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

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms of TB (such as persistent cough, fever, or weight loss), live in an area with higher TB risk, or have been exposed to someone with TB. It’s also used in screening for latent TB infection or monitoring treatment response.

How the Test Works

The test extracts DNA from your blood sample and uses a specialized probe to detect genetic sequences unique to *M. tuberculosis*. If the probe binds to these sequences, it confirms the presence of the bacteria’s DNA.

Sample Collection

A small blood sample is drawn from your arm, similar to a routine blood test. The sample is processed in a lab to isolate DNA for testing.

What to Expect After the Test

Results are typically available within 24–48 hours. If positive, further testing (like culture or additional molecular tests) may follow to confirm diagnosis and guide treatment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

MTBC DNA Probe Test (Blood)

Frequently asked questions

How long does it take to get results?
Results are usually ready within 24–48 hours after the lab processes your sample.
Can this test detect latent TB?
No, this test specifically looks for active TB infection by detecting *M. tuberculosis* DNA. For latent TB, a different screening test (like a TB skin test or IGRA) is typically used.
Is this test painful?
The blood draw is mild discomfort similar to a standard venipuncture, but the actual testing process is quick and non-invasive.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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