Florida Bureau of Public Health laboratories
Acid-Fast Bacilli smear
The AFB smear test provides results for the detection of acid-fast bacilli by fluorescent staining by Auramine-O method, light microscopy by Ziehl-Neelsen staining.
Analyte(s)
Acid-Fast bacilli bacteria
Test Code
Part of test code 3100
Testing Location
Jacksonville Laboratory
Testing Department
Mycobacteriology (TB)
Pre-approval Required?
No
Required Forms
BPHL Test Requisition, DH1847
(not needed if orders are placed via electronic order)
Minimum Volume
At least 5 mL of unprocessed specimen or 0.5 – 1 mL of processed specimen
Turn Around time
1 business day after receipt at the laboratory.
Supply Ordering
Supplies may be requested from your servicing laboratory. Supplies ordered from the BPHL should only be used for specimen sent to the BPHL for testing.
Collection Media
50 mL sterile conical tube.
Specimen Sources
Multiple specimen types acceptable. Sputum or other respiratory samples (5 mL minimum).
Processed specimens are acceptable.
Air-dried smears may be submitted – for AFB smear only (No AFB culture.)
AFB smears cannot be performed on blood specimens.
Specimen Labeling
Specimen must be labeled with at least two unique patient identifiers, e.g., name and DOB.
Information on the specimen must match the requisition and/or test order.
Special SPecimen Preparation
At least 5 mL of unprocessed specimen or 0.5 – 1 mL of processed specimen in 50 mL sterile conical tube, shipped in double container. Gastric lavage specimens must be neutralized with 100 mg of sodium carbonate if the time between collection and processing exceeds 4 hours.
Storage Conditions
Store specimens refrigerated at 2 – 8o C until time of shipment.
Packaging and Shipping
Specimens can be shipped within the 2-28o C temperature range,
Urine specimens must be shipped refrigerated (2 – 8o C). Processed urine sediments may be shipped within the 2-28o C temperature range and must be clearly marked on the requisition as “Processed.” Air-dried smears should be placed in a slide holder during shipment, stored and shipped within the 2-28o C temperature range.
Separation of specimens to prevent cross-contamination.
unsatisfactory specimen
1) Formalin fixed or paraffin-embedded tissues.
2) No patient identification on specimen tube.
3) No specimen observed in specimen container.
4) Specimen damaged or leaked entirely in transit.
5) Gastric aspirates that have not been neutralized.
6) Urine specimens arriving outside of acceptable temperature range.
7) AFB Smear cannot be performed on blood specimens.
8) Samples cross contaminated due to sample leaking in transit.
Interferences and Limitations
Blood specimens
Reference Range
Negative (Not Detected)
Result Indicator
Positive: (+/-, 1+, 2+, 3+, 4+) with quantitation per unit area
Negative: No AFB seen.
Reference lab
None
Reflex testing
Positive smear specimens will reflex to rtPCR for all new patients or when >6 months since last rtPCR test (cannot be done if only air-dried smear submitted).
Contact Information
904-791-1630
904-791-1633, fax