#15320: AFB Stain
(AFB)

COMPONENTS
Name Method Reference Range Units
Specimen Source  
Acid-fast Bacilli Stain STAIN No AFB Seen  

SPECIMEN REQUIREMENTS
No Type Volume Temperature Container Type Instructions
1 Sterile Container/Tube 2 (1) mL Ambient - 24 Hour(s)/Refrigerated - 7 Day(s) Sterile  
2 Gastric Aspirate Refrigerated - 7 Day(s)/Ambient - 24 Hour(s) Sterile  
3 Fluid 10 (5) mL Frozen - 2 Month(s)/Refrigerated - 7 Day(s)/Ambient - 24 Hour(s) Sterile  
4 Culturette/Swab 1 (1) mL Refrigerated - 7 Day(s)/Ambient - 24 Hour(s) Culturette  
5 CSF 3 (1.5) mL Frozen - 2 Month(s)/Refrigerated - 7 Day(s)/Ambient - 24 Hour(s) Sterile  
6 Whole Blood Isolator Tube 10 (5) mL Ambient - 24 Hour(s) Black/Yell  
7 Nasopharyngeal Swab 1 (1) mL Ambient - 24 Hour(s)/Refrigerated - 7 Day(s) Sterile  
8 Urine 10 (5) mL Refrigerated - 7 Day(s)/Ambient - 24 Hour(s)/Frozen - 2 Month(s) Sterile  
9 Tissue 1 (0.5) g Refrigerated - 7 Day(s)/Ambient - 72 Hour(s) Sterile Place tissue & needle biopsies in Middlebrook broth./// 
10 Stool 2 (1) g Refrigerated - 7 Day(s)/Ambient - 24 Hour(s) Stool  

GENERAL INFORMATION
Setup Schedule Sunday-Saturday
Reported 2 days
CPT Code 87206
Notes 1. AFB smear result shall be used as an adjunct in evaluating patient's mycobacterial disease (e.g. tuberculosis); AFB culture is highly recommended for laboratory diagnosis. 2. Source of specimen is required, please include on requisition. 3. AFB stain will be performed on whole blood; however, mycobacteria are often present in either very low concentrations or intermittently in peripheral blood. AFB blood stains may therefore yield false negative results. Interpret these results with caution. 4. The Mycobacterium Tuberculosis Direct (MTD), a target-amplified nucleic acid probe is available for respiratory specimens. Call technical services for details. Prices might not include a handling fee.
Clinical Utilities Aid in the early diagnosis of mycobacterial infections. A negative smear does not rule out mycobacterial infection.

COLLECTION INSTRUCTIONS
1. Collect specimen in a sterile, leakproof container.

2. For respiratory specimens, collect three sputum samples from

deep productive coughs in consecutive 8 to 24 hour intervals per CDC

guidelines (at least one should be an early morning specimen).

3. Place tissue and needle biopsies in Middlebrook broth (available

from Specialty) or in sterile saline.

4. Culturette and nasopharyngeal swab collections may result in a

potential decline in sensitivity of Mycobacterium isolation in

culture. The yield of material is limited and, due to the

hydrophobicity of Mycobacteria, the organisms may be entrapped

within the fiber matrix and not readily transition into solution or

onto media. False negative cultures are possible, especially if few

pathogens are present.

5. If gastric aspirate cannot be shipped immediately, add 100mg of

sodium bicarbonate as a buffer to neutralize any acid detrimental to

Mycobacteria.

6. Refrigerate all samples within 1 hour of collection time except for

whole blood samples.

7. Ship specimens on cold pack within 24 hours of collection. Whole

blood is shipped at ambient temperature.



Smear preparation:

1. Place at least 2 drops of specimen onto a prelabeled clean

microscopic slide. Use decontaminated specimens if the source is

obtained from non-sterile body sites.

2. Air-dry. Gently heat-fix smears. Specimen should be visible after

drying.

3. Ship to Specialty in slide holder at ambient temperature.