Acid-Fast Bacilli (AFB) Culture and Smear, Non-Blood

Sunquest Code:AFBC & AFBSTS  
Epic Code:LAB877, LAB266  
Order Instructions:Order both AFBC and AFBSTS
Synonyms:AFB Culture and Smear; Mycobacterium Culture; TB Smear; STAT AFB; AFBC; AFBSTS
Methodology:Standard reference procedures for stain and culture.
Test Includes:Smear and culture for acid fast bacilli. Identification of AFB is ordered and billed separately. DNA probes are available for M. tuberculosis complex and M. avium-intracellulare complex as indicated. DNA sequencing and other molecular techniques are used for identification of other mycobacteria species.
Turnaround Time:Specimens are sent to reference laboratory Mon-Sun; routine smears are reported within 24 hours of receipt at reference lab; contact the Microbiology Lab if needed stat. Positive cultures are reported when detected, negative cultures in 8 weeks.
Special Instructions:A subsequent culture should be performed on specimens with a negative smear result. Indicate if Mycobacteria other than tuberculosis (MOTT) are suspected. Provide patient's PPD status, BCG immunization history and prior antituberculosis therapy.

Collection Instructions

Specimen:Body fluids, CSF, gastric aspirate, respiratory, sputum, tissue, urine. Swabs are not acceptable for AFB testing and will be rejected.
Optimal Volume:See Collection Instructions.
Container:Plastic leakproof container, sterile (Syringe, sterile, no needle)
Collection Instructions:

SWABS are not acceptable for AFB testing and will be rejected.

  • Respiratory Specimens: 5-10 mL; 1 mL minimum
  • Body Fluids or CSF: 5 mL; 1 mL minimum
  • Gastric Aspirates: 5-10 mL; 1 mL minimum
  • Tissue: Sample must be visible. Sterile container with saline.
  • Urine: 40 mL; 10 mL minimum in sterile container
Causes for Rejection:Swabs or dry material collected and transported on a swab.
Acid Fast Stain will not be performed on: Stool, blood, bone marrow, grossly bloody specimens, CSF if less than 5 mL, or urine specimens if less than 40 mL, however these samples will be cultured.
Specimen volumes below minimum per specimen source.

Processing and Shipping

Specimen Processing:Store in refrigerator. Gastric lavage specimens must be neutralized with sodium carbonate if transport is delayed for more than four hours.
Shipping Instructions:Ship at refrigerated temperature.
Stability:Non-respiratory specimens: 24 hours at room temperature; 1 week refrigerated; 1 week frozen.
Respiratory specimens: unacceptable at room temperature, 1 week refrigerated; 2 weeks frozen.  
Test Performed at or Referral Lab Lab Sendouts  (ARUP)
Referral Lab number:see Comments section


Critical Range:Positive/Growth
Reference Range:Negative/No growth

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