AFB staining and culture are standard methods for detecting Mycobacterium tuberculosis and related species.

The test involves microscopic examination of sputum after special staining (Ziehl‑Neelsen or Auramine‑O).

Clinical uses include:

Confirming suspected pulmonary tuberculosis.

Monitoring infectivity and treatment response in TB patients.

Detecting non‑tuberculous mycobacteria (NTM) in chronic lung disease.

Often performed alongside chest X‑ray, GeneXpert MTB/RIF, and culture methods for comprehensive TB diagnosis.

Analyte: Acid‑fast bacilli in sputum.

Normal Result: No AFB detected.

Abnormal Findings:

Positive AFB smear: Indicates active TB or NTM infection.

Negative smear but clinical suspicion: May require culture or molecular testing for confirmation.

Clinical Use:

Provides a direct marker of TB infection and infectivity.

Helps guide diagnosis, treatment initiation, and monitoring.

Supports pulmonology and infectious disease evaluations.