Quick Reference
- Full form
- Acid-Fast Bacilli Smear (Ziehl-Neelsen Stain)
- Sample type
- Sputum or Body Fluid
- Fasting
- Not required
- Marker measured
- 1
- Report turnaround
- Same day
- Available at
- All locations
About AFB Smear / ZN Stain
An AFB Smear with ZN staining is a quick microscopic check for tuberculosis bacteria in sputum or other body fluid. Because TB bacteria have a waxy coating that resists normal stains, the Ziehl-Neelsen (ZN) method is used specifically to make them visible under the microscope.
This test is usually the fastest way to get an initial answer while waiting for slower culture-based confirmation. No fasting is needed, and it is commonly requested for patients with a persistent cough lasting more than two weeks.
How to Prepare
- No fasting required.
- Bring your sample in a clean, dry container, or ask our team about proper collection at the time of your visit.
Frequently Asked Questions
What does an AFB smear test check for?
It checks for acid-fast bacteria, most commonly the bacteria that cause tuberculosis, using a specialised ZN stain that makes them visible under the microscope.
Who should get an AFB smear test?
Anyone with a persistent cough lasting more than two weeks, unexplained weight loss, or night sweats is commonly advised to get this test.
Is an AFB smear the same as a TB culture?
No, a smear gives a fast preliminary result while a culture takes longer but confirms the exact bacteria and its drug sensitivity.
Do I need to prepare specially for this test?
No special preparation is needed, though your doctor will guide you on collecting an early morning sputum sample for the best accuracy.
How soon will I get my AFB smear result?
Same day, since this is a rapid microscopic examination.
Is home sample pickup available for sputum tests?
Yes, our team can guide you on home collection in all City Care Lab service areas.
This page provides general health information and is not a substitute for medical advice. Speak with your doctor about your specific results and treatment.