Test ID: SAFB
Acid-Fast Smear for Mycobacterium
NY State Approved 
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Detection of acid-fast bacilli in clinical specimens
Method Name A short description of the method used to perform the test
Auramine-Rhodamine Stain
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Acid-Fast Smear for Mycobacterium
AFB (Acid-Fast Bacilli)
Bacillus, Acid-Fast
MTB (Mycobacterium tuberculosis)
Mycobacterium tuberculosis (MTB)
Smear, Acid-Fast Bacilli (AFB)
TB (Tuberculosis)
Tubercle Bacilli: Mycobacterium tuberculosis
Tuberculosis (TB)
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 to the laboratory promptly. 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.
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 Type | Temperature | Time |
|---|---|---|
| Varies | Refrigerated (preferred) | 7 days |
| Ambient | 7 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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. Detection of acid-fast bacilli in sputum specimens allows rapid identification of individuals who are likely to be infected while definitive diagnosis and treatment are pursued.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative (reported as positive or negative)
Interpretation Provides information to assist in interpretation of the test results
Patients whose sputum specimens are identified as acid-fast positive should be considered potentially infected with Mycobacterium tuberculosis, pending definitive diagnosis by molecular methods and/or mycobacterial culture.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
MTBRP/88807 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.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Pfyffer GE, Brown-Elliot BA, Wallace RJ: General characteristics, isolation, and staining procedures. In Manual of Clinical Microbiology. 8th edition. Washington, DC, ASM Press, 2003, pp 532-559
Method Description Describes how the test is performed and provides a method-specific reference
Auramine-rhodamine fluorochrome stain prepared and read with fluorescent microscope. (Methcock B, Nolte FS, Wallace, R: In Manual of Clinical Microbiology. 7th edition. Washington, DC, ASM Press, 1999, pp 399-437)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Sunday; Continuously
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
87206
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| SAFB | Acid Fast Smear For Mycobacterium | In Process |
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