Mycobacterium Tuberculosis Culture (Sputum or Other Respiratory Specimen)
This test checks for the presence of *Mycobacterium tuberculosis*, the bacterium responsible for tuberculosis (TB). It involves growing a sample of your respiratory secretions (like sputum) to identify TB bacteria.
["A positive culture confirms TB infection, guiding treatment decisions."]
Key facts at a glance
- LOINC
- 107179-4
- Short code
- Mycobacterium Drain Cult
- Synonyms
- Mycobacterium Drain Cult
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- organism-specific-culture
- 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 Is This Test Done?
Your healthcare provider may order this test if you have symptoms like persistent cough, chest pain, fever, or weight loss—especially if you live in an area with higher TB rates or have risk factors like weakened immunity. It’s also used to monitor treatment progress or detect TB in people who don’t have symptoms.
How Is the Test Performed?
You’ll cough into a sterile container (sputum sample) or provide another respiratory secretion (e.g., nasal swab). The sample is sent to a lab, where it’s grown in a controlled environment to detect TB bacteria. Results can take weeks to months.
What Does a Positive Result Mean?
A positive result means TB bacteria were found in your sample. This confirms an active infection and helps your doctor start the right treatment (usually antibiotics). False positives are rare but possible.
What If the Test Is Negative?
A negative result means no TB bacteria were detected in this sample. However, TB can be hard to grow in the lab, so repeated testing or other tests (like a TB skin test or blood test) may be needed. False negatives can occur if the sample wasn’t collected correctly or the infection is very early.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is critical for diagnosing active TB, especially in high-risk groups. It helps confirm whether TB is present before starting treatment, ensuring you receive the most effective antibiotics. Culture results also guide doctors to adjust treatment if the bacteria develop resistance. Without this test, TB could go untreated or misdiagnosed, leading to complications or spread.
Short name
Tuberculosis Sputum Culture
Frequently asked questions
How long does it take to get results?
Can I take antibiotics before getting this test?
What if I have a positive culture but no symptoms?
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