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Test ID: SAFB    
Acid-Fast Smear for Mycobacterium

Specimen Type Describes the specimen type needed for testing


Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

Container/Tube: Sterile container

Specimen Volume: Entire collection

Collection Instructions:

1. Sputum collection recommendations:

a. Collect 3 sputum specimens for acid-fast smears and culture in patients with clinical and chest X-ray findings compatible with tuberculosis.

b. These 3 samples should be collected at 8- to 24-hour intervals (24 hours when possible) and should include at least 1 first-morning specimen.

c. Specimens must be delivered promptly to the laboratory. Specimens that cannot be processed within 1 hour of collection should be refrigerated during transport and stored refrigerated in the laboratory prior to processing.

Forms: If not ordering electronically, submit a Microbiology Request Form (Supply T244) with the specimen.

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

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 piec

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected








Blood or serum


Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
VariesRefrigerated (preferred)7 days
 Ambient 7 days