TB DNA PCR test
Quick answer: This test looks for the genetic material (DNA) of Mycobacterium tuberculosis in a sample. Doctors order it when tuberculosis is suspected in the lungs, urinary tract, joints or other sites.
- SampleUrine, sputum or tissue
- TakesA few minutes to give a urine or sputum sample
- Before the testFor sputum or urine, an early-morning sample is usually preferred; staff will explain how to collect it.
- In fertility careGenital tuberculosis is a known cause of blocked tubes and a thin uterine lining in India, so doctors may test for TB during an infertility work-up.
How the test is done
- 1Staff explain which sample is needed and how to collect it
- 2For urine or sputum, collect an early-morning sample in the sterile container
- 3Tissue samples are taken by a doctor during a procedure
- 4The lab uses PCR to look for Mycobacterium tuberculosis DNA
What your results can mean
Reading your report
A detected result supports a TB diagnosis, but a negative result does not always rule it out; your doctor reads it with your other tests.
If the result is outside the usual range
A detected result supports a TB diagnosis in the site tested, such as the lungs, urinary tract or endometrium. A negative result does not always rule TB out, and positive results can occasionally occur without active disease.
Who usually has this test
People with suspected TB in the lungs, kidneys, joints or lymph nodes, and some women with infertility where genital TB is considered.
Risks and aftercare
Urine and sputum collection have no risks; follow staff advice after any tissue sampling.
Names and options
Also called: TB PCR, Mycobacterium tuberculosis PCR, MTB PCR
Options
- Urine
- Sputum
- Synovial tissue
Listed by the hospital as
- TB DNA PCR, URINE
- TB DNA PCR, SPUTUM
- TB DNA PCR, SYNOVIAL TISSUE
Questions about this test
Should I start TB treatment on a positive PCR alone?
Doctors usually look at symptoms, scans, biopsy and other tests before starting TB treatment. Discuss your result fully with your doctor.
How is genital TB linked to infertility?
Genital TB can damage the fallopian tubes and the lining of the womb. It often has no symptoms and is found during fertility tests.
Can TB PCR be falsely positive?
Yes, occasionally, especially in endometrial samples. That is why a positive PCR alone is not enough reason to start a long TB course without other evidence.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
Waiting area
IVF lab
This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.