AFB Isolate Identification

Brief Description

The Mycobacteriology Unit accepts specimens from both public and private healthcare providers for the isolation and identification of Mycobacterium tuberculosis (MTB) as well as nontuberculous mycobacteria (NTM) which can cause opportunistic infections in immunocompromised individuals.

Laboratory Unit



  • Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF)
  • 16S rRNA Gene Sequencing

Specimen Collection

AFB Culture Isolates:

Pure cultures submitted on solid media such as Middlebrook 7H10/7H11 or Lowenstein-Jensen slants. Cultures submitted in liquid 7H9 broth, MGIT, BacT/Alert MP bottles, VersaTREK bottles.


  • AFB Culture Isolates submitted in slants or bottles can be maintained at room temperature (15-30°C) during transit and must be wrapped in absorbent cushioning material before being placed inside the appropriate shipping container (Category A for MTB isolates, Category B for all other mycobacteria). 
  • MGITs submitted for identification and/or susceptibility testing must be placed inside a plastic 50 mL conical tube, capped securely, and packaged according to federal shipping regulations. 
  • Isolates identified as Mycobacterium tuberculosis complex must be shipped as DOT Category A infectious substances according to IATA regulations.
  • Download this pdf file. FRM-QA 4 Refrigeration Outfit Guide

Acceptable Specimen Type(s)

AFB Culture Isolates

Test Request

Possible Results

  • Identification of mycobacteria species
  • No mycobacteria found
  • Unsatisfactory

Reference Range


Unacceptable Conditions

  • Missing testing requisition
  • Missing minimum of 2 patient identifiers
  • Improper labeling
  • Improper storage/transport of specimen
  • No specimen received (empty collection tube).
  • Wrong specimen type
  • Specimen damaged, broken, or leaking upon arrival

Interfering Substances


Result Reported

7 business days


Download this pdf file. Fee schedule

LOINC/Order Codes

9825-1 (Order code: 34000)