AFB culture & smear-6617

Test info

AFB culture & smear
Acid fast bacteria

Identification, susceptibilities and serogrouping will be performed on all microbiology isolates considered by the laboratory to be significant.


Varies (see collection instructions)

Sterile container


Varies (see collection instructions)
Specimen Recommended quantity Special instructions
Body fluid Adult: >10mL
Child (≤14 yrs): ≥1mL
If specimen might clot, place in a sterile sodium heparin tube (Lithium heparin and EDTA are unacceptable). Transport refrigerated.
Bone marrow As much as possible Collect aseptically in sodium heparin (Lithium heparin is unacceptable). Do not refrigerate; transport at ambient (room) temperature.
Bronchial washing Adult: ≥5mL
Child (≤14 yrs): ≥1mL
Gastric 5 – 10mL Collect early morning fasting specimen on 3 consecutive days. Transport refrigerated.
Spinal fluid 3 – 10mL Transport refrigerated
Sputum 5 – 10mL Patient should rinse mouth out vigorously with water (not mouthwash), before producing sputum

Obtain at least three consecutive sputum specimens, each collected in 8-24 hr intervals, with at least one being an early morning specimen because respiratory secretions pool overnight.

Unacceptable : More than one specimen in an 8 hour period.
Transport refrigerated.
Stool Pea-sized amount Transport refrigerated
Swab/skin   Swabs are the least desirable specimen for isolation of Mycobacteria. Whenever possible, tissue biopsies or aspirated material is recommended for skin lesions and other sources.
Transport refrigerated
Urine Adult: >40mL
Child (≤14 yrs): 10mL
Three (3) clean catch early morning specimens are recommended.
Transport refrigerated.

Submit entire specimen


Sterile container



ESwab or other bacterial culture swab (acceptable, but not preferred)


ESwab or other bacterial culture swab (acceptable, but not preferred)


Refrigerated - 2 weeks

  • Improper label (unlabeled or mislabeled)
  • Time delay between time of collection and receipt of specimen
  • Inappropriate timing of collection
  • Improper transport container
  • Improper transport temperature
  • Interfering substances
  • Inappropriate specimen type
  • Expectorated sputum with oropharyngeal contamination
  • Leaking container


AHL - Microbiology: M
Smear - 1 day
Culture - 6 weeks

Culture and acid fast stain

Clinical and Interpretive info


Tuberculosis is caused by Mycobacterium tuberculosis complex and ranges from asymptomatic infection to pulmonary disease, as well as infection of the genitourinary tract, lymph nodes, CNS, bones and joints, peritoneum, pericardium and larynx. M. tuberculosis is transmitted via droplet nuclei generated by coughing, and suspended by normal air currents. Nontuberculous mycobacteria are ubiquitous in the environment and may also cause disease, but are not usually transmitted from person-to-person. M. avium complex causes pulmonary infections and, in HIV-infected patients, disseminated disease. M. fortuitum, M.chelonae, M. abscessus, M. kansasii, M. marinum. M.szulgai, M. scrofulaceum, and other mycobacteria cause cutaneous, pulmonary, bacteremia, or other diseases. M. gordonae is typically nonpathogenic.


Additional CPT codes:
87186 - Sensitivities (if appropriate)
87077 - ID (if appropriate)
This list may not be all inclusive if there is the need to send the ID or sensitivities out to a referral laboratory