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Mycobacterium tuberculosis RNA Detection (Qualitative) by Probe-Based Molecular Assay

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

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

Quick summary

["A positive result may indicate active TB, guiding treatment decisions."]

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

Key facts at a glance

LOINC
74733-7
Short code
Deprecated Mycobacterium rRNA Bld Pos Prb Mag
Synonyms
Deprecated Mycobacterium rRNA Bld Pos Prb Mag
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-mag-capture
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

How the Test Works

The test uses a molecular method to detect specific genetic sequences from *Mycobacterium tuberculosis* in your sample. If the bacteria are present, the test can identify their DNA or RNA, confirming infection.

What to Expect Before the Test

No special preparation is needed. Your healthcare provider may collect a sample from your respiratory secretions (like sputum) or another bodily fluid, depending on clinical guidelines.

What the Results Mean

A positive result suggests the presence of *Mycobacterium tuberculosis* genetic material, which may mean you have an active TB infection. A negative result means the test did not detect the bacteria’s genetic material in this sample.

When You Might Need This Test

This test is often used in people with symptoms of TB (such as cough, fever, or weight loss), those exposed to TB, or individuals with weakened immune systems. It may also be part of screening in high-risk groups.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is critical for diagnosing active TB, especially in cases where traditional culture methods take longer. Early detection allows for prompt treatment with antibiotics, which can prevent progression to severe disease and reduce transmission to others.

Short name

TB RNA Probe Test

Frequently asked questions

Why might I need this test?
Your doctor may recommend this test if you have symptoms of TB, have been exposed to someone with TB, or belong to a group at higher risk (e.g., immunocompromised individuals, travelers to high-risk areas).
What does a positive result mean?
A positive result strongly suggests an active TB infection. Your healthcare provider will work with you to confirm the diagnosis and start appropriate treatment, which may include antibiotics.
Can I get TB from a positive test result?
No, a positive test result indicates the presence of *Mycobacterium tuberculosis* in your body, meaning you are infected and may be contagious. However, treatment can clear the infection and prevent further spread.
  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