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Test ID: SAFB    
Acid-Fast Smear for Mycobacterium

Specimen Type Describes the specimen type needed for testing

Varies

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.

Specimen source is required.

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

 

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 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

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

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