Microbiology• Updated 21 October 2026
CBNAAT / GeneXpert TB Test
A rapid molecular test that detects TB and resistance to rifampicin within about two hours.
Results: Within a day Specimen: Sputum or other samples
Quick Summary
Primary Purpose
To diagnose TB quickly and check for drug-resistant TB.
What It Measures
TB DNA and rifampicin resistance genes.
Preparation
As for a sputum sample.
Overview
CBNAAT and TrueNat are widely used under India's TB programme.
They detect TB even when smear tests are negative.
What It Measures
TB detected
Yes or no.
Rifampicin resistance
Detected or not.
How It's Performed
- 01
Sample
Sputum or other sample collected.
- 02
Test
Processed in a machine.
- 03
Result
Usually within hours.
Interpreting Results & Next Steps
Discuss with Doctor
Your doctor will explain what your result means and what happens next.
If values are High:
TB detected means treatment is needed; resistance means a different regimen.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Tuberculosis Screening(opens in a new tab) · MedlinePlus, US National Library of Medicine