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Acid Fast Bacilli (AFB) Culture (LAB000991)
Test Mnemonic:


Specimen Requirements:

Acceptable specimens include Aspirate/ Abscess/ Wounds, BALs, Bronchial washes, Body fluids, Bone, CSF, Ocular specimans, Feces, Gastric Lavages, Sputum, Tissue/Biopsies, Urine (PCN collections only).


Collection technique varies by specimen. 

When clinically indicated for suspected MTB cases, it is recommended that 3 sputum samples are collected at 8-24 hour intervals with at least one specimen being an early morning collection. For sputum collection information, refer to UTMBs Specimen collection guidelines in the Laboratory Test Directory. 


Acceptable specimen containers include Anaerobic transport medium, Eswab™, Falcon tubes, red top tubes with no additive, and sterile containers. 

Minimum Volume:


Specimens sent with multiple test requested and insufficient volume for all the tests will be prioritized based on clinical importance from the provider. 


Room temperature: CSF, Body fluids, Ocular specimens, Gastric lavages, and tissues/ biopsies. 

Refrigerated: Urine, Abscess/ Wounds, Feces, Respiratory sources. 


Stability is dependent on the source and collection container. 

Specimens in non-preserved containers are stable up to 24 hours at appropriate storage. 

Specimens in preservative containers are stable up to 48 hours at appropriate storage. 


Sputum samples will be accepted up to 72 hours from collection at appropriate storage. 

Causes for Rejection:

Urine PCN volumes <40mL. 

Urine received in preservitive tubes. 

Cary-Blair transport medium. 

Tissues/Biopsies in formalin. 

Specimens found to be under-labeled, mislabeled, or leaking containers. 

Reference Range:

No Acid- Fast bacilli isolated.

Turnaround Time:

Smears are read and reported within 24 hours of receipt in the lab, when clinically indicated. 

Cultures are held for 6 weeks and read once per week. 

Positive cultures with susceptibility testing will have extended turnaround times. 


Acid fast smear and culture for the isolation and identification of Mycobacterium species; antimicrobial susceptibility testing when appropriate.


Clinical Microbiology


AFB culture, Mycobacteria culture, MTB, MTBC, M. Bovis, NTM, MAC

Clinical Indication:

Supspected Mycobacterial infection. 

Suspected Mycobacterial infections from normally sterile body sites, such as  bone marrow, bone marrow core, CSF, tissues and body fluids



CPT 4 Code:

Culture: 87116, Smear: 87206, additional CPT codes may apply. 

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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