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Mycobacterium tuberculosis Culture from Cerebrospinal Fluid (Qualitative)

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

This test checks for the presence of *Mycobacterium tuberculosis*—the bacteria responsible for tuberculosis—in your cerebrospinal fluid (CSF). It helps diagnose whether an infection has spread to the brain or spinal cord.

Quick summary

["A positive result may indicate meningitis or spinal tuberculosis; a negative result does not rule out infection."]

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

Key facts at a glance

LOINC
107013-5
Short code
Mycobact prelim grow CSF Ql Cult
Synonyms
Mycobact prelim grow CSF Ql Cult
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
organism-specific-culture
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like severe headaches, neck stiffness, fever, confusion, or neurological problems—especially if you have a history of tuberculosis or live in an area with higher infection rates. It’s also used to monitor treatment progress in people already diagnosed with TB.

How the Test Works

A small sample of your CSF is collected via a spinal tap (lumbar puncture). The fluid is then cultured in special media to detect *M. tuberculosis* growth over weeks. No special preparation is needed, but you may be asked to avoid certain medications that could interfere with results.

What to Expect

The procedure takes about 15–30 minutes. You’ll lie on your side, and a needle is inserted into your lower back to draw fluid. You may feel a brief pinch, but it’s usually not painful. Afterward, you’ll rest for a few minutes before returning to your usual activities.

Results and Follow-Up

Results can take 2–8 weeks or longer. A positive culture confirms *M. tuberculosis* infection, while a negative result means no bacteria were detected in that sample. Follow-up tests or treatments may be recommended based on your doctor’s assessment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

CSF Mycobacterium Tuberculosis Culture

Frequently asked questions

What does a positive result mean?
A positive culture indicates *Mycobacterium tuberculosis* is present in your CSF, strongly suggesting a central nervous system infection (e.g., tuberculous meningitis). This requires immediate medical evaluation, often including additional imaging, further cultures, or treatment with anti-tuberculosis drugs.
What if the test is negative?
A negative result means no *M. tuberculosis* was detected in this sample, but it doesn’t rule out infection entirely. Other causes of meningitis (e.g., viral, fungal, or bacterial infections) could explain your symptoms. Your doctor may repeat the test or order different tests (e.g., PCR, imaging) to investigate further.
How long does it take to get results?
Results typically take 2–8 weeks, depending on the lab’s processing time and whether the bacteria grow. Your doctor will contact you once results are available, but delays are common due to the slow growth of *M. tuberculosis*. Avoiding stress or infection during testing can help ensure accurate results.
  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