Acid-Fast Bacillus (AFB) Identification
Ordering Recommendation

Identify mycobacterial isolates, including requests for speciation within the M. tuberculosis complex.

Identification. Methods may include biochemical, mass spectrometry, nucleic acid probe, polymerase chain reaction, or sequencing.
Varies (depends on organism growth)
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Actively growing organism, in pure culture. 
Specimen Preparation
Place each specimen in an individually sealed bag. Transport sealed container with pure culture on solid or in liquid media. 
Storage/Transport Temperature
Room temperature. If culture is suspected of being a microorganism identified on the IATA list as an infectious substance affecting humans, submit specimen according to Infectious Substance, Category A, shipping guidelines. 
Unacceptable Conditions
Mixed cultures or non-viable organisms. Organisms submitted on an agar plate. 
Indicate source of organism and any other pertinent information, such as the growth rate of the organism or DNA probe results. 
Ambient: 2 weeks; Refrigerated: 2 weeks; Frozen: 2 weeks 
Reference Interval
Complete identification of clinically significant isolates.
Interpretive Data
For identification by DNA sequencing and MALDI-TOF:

Statement B: Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

If the isolate M. tuberculosis complex is to be speciated, enter this information in the comment field and ship Category A.
A processing fee will be billed for all organisms submitted that are not in pure culture, as indicated in specimen requirements.
Identification of AFB isolates is billed by individual tests performed.

Probes can be performed directly from Middlebrook 7H9 broth. MGIT is not suitable for direct probe testing.
Hotline History
CPT Code(s)
CPT codes for identification vary based on method.
Component Test Code*Component Chart NameLOINC
0060999AFB Identification543-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please view this test within the Laboratory Test Directory found at
  • AFB identification by sequencing, 16S rRNA
  • M. tuberculosis identification
  • Mycobacterium tuberculosis Probe