Test ID SAFB Acid-Fast Smear for Mycobacterium
Useful For
Detection of acid-fast bacilli in clinical specimens
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
TBT | Mycobacteria Culture, Conc | No, (Bill Only) | No |
TISSR | Tissue Processing | No, (Bill Only) | No |
Testing Algorithm
When this test is ordered, the reflex tests may be performed and charged.
Method Name
Auramine-Rhodamine Stain
Reporting Name
Acid Fast Smear For MycobacteriumSpecimen Type
VariesMicrobiology Test Request Form (T244) (http://www.mayomedicallaboratories.com/it-mmfiles/microbiology_test_request_form.pdf
Neurology Test Request Form-General (T732) (http://www.mayomedicallaboratories.com/it-mmfiles/neurology-request-form.pdf)
General Test Request Form (T239) (http://www.mayomedicallaboratories.com/it-mmfiles/general-request-form.pdf)
Specimen source is required.
Submit only 1 of the following specimens:
Specimen Type: Body fluid
Container/Tube: Sterile container
Specimen Volume: 1 mL
Specimen Type: Bone marrow
Container/Tube: SPS/Isolator System or green top (lithium heparin)
Specimen Volume: Entire collection
Specimen Type: Gastric washing
Container/Tube: Sterile container
Specimen Volume: 10 mL
Collection Instructions: Neutralize specimen within 4 hours of collection with 100 mg of sodium carbonate per 5 to 10 mL of gastric wash.
Specimen Type: Respiratory
Sources: Bronchoalveolar lavage fluid, bronchial washing, sputum
Container/Tube: Sterile container
Specimen Volume: 4 mL
Collection Instructions: Collect 3 respiratory specimens for acid-fast smears and culture in patients with clinical and chest X-ray findings compatible with tuberculosis. These 3 specimens should be collected at 8- to 24-hour intervals (24 hours when possible) and should include at least 1 first-morning specimen.
Specimen Type: Stool
Container/Tube: Sterile container
Specimen Volume: 5-10 g
Specimen Type: Tissue
Container/Tube: Sterile container
Specimen Volume: 5-10 mm
Collection Instructions: Collect a fresh tissue specimen.
Specimen Type: Urine
Container/Tube: Sterile container
Specimen Volume: 2 mL
Collection Instructions: Collect a random urine specimen.
Specimen Type: Swab
Additional Information: Fresh tissue or body fluid is the preferred specimen type instead of a swab specimen. Recovery of mycobacteria and aerobic actinomycetes from swabs is variable.
Sources: Wound, tissue, or body fluid
Container/Tube: Culture transport swab (noncharcoal) Culturette
Specimen Volume: Adequate specimen
Collection Instructions:
1. Before collecting specimen, wipe away any excessive amount of secretion and discharge, if appropriate.
2. Obtain secretions or fluid from source with sterile swab.
3. If smear and culture are requested or both a bacterial culture and mycobacterial culture are requested, collect a second swab to maximize test sensitivity.
Specimen Minimum Volume
Varies; If mycobacterial culture is also requested, then 1.5 mL for body fluid, 3 mL for respiratory specimen, or a pea-sized piece of fresh tissue. If smear only is requested, then 0.5 mL for body fluid, 3 mL for respiratory specimen, or a pea-sized piece of fresh tissue.
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Varies | Refrigerated (preferred) | 7 days |
Ambient | 7 days |
Clinical Information
Mycobacterium tuberculosis is a leading infectious disease cause of death worldwide. The Centers for Disease Control and Prevention has reported a rise in the incidence of tuberculosis associated with AIDS, foreign-born cases, and increased transmission in high-risk populations. There has also been a rise in the number of Mycobacterium tuberculosis strains that exhibit resistance to 1 or more antituberculosis drugs. The public health implications of these facts are considerable. Because Mycobacterium tuberculosis is readily spread by airborne particles, rapid diagnosis and isolation of infected persons is important. Nontuberculous mycobacteria infections also cause significant morbidity and mortality in humans, particularly in immunocompromised persons. Detection of acid-fast bacilli in sputum specimens allows rapid identification of individuals who are likely to be infected with mycobacteria while definitive diagnosis and treatment are pursued.
Reference Values
Negative (reported as positive or negative)
Cautions
MTBRP / Mycobacterium tuberculosis Complex, Molecular Detection, PCR is the preferred test for rapid, direct detection of Mycobacterium tuberculosis from clinical specimens.
Artifacts may exhibit nonspecific fluorescence and be confused with organisms.
Day(s) Performed
Monday through Sunday; Continuously
Report Available
1 dayPerforming Laboratory

Test Classification
This test uses a standard method. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
87206
87176-Tissue processing (if appropriate)
87015-Mycobacteria culture, concentration (if appropriate)