ARUP's Laboratory Test Directory
| 0060095: Mycobacterium tuberculosis Amplified Direct Detection |
| Test Mnemonic: MC MTD | |
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Methodology: Transcription Mediated Amplification (Gen-Probe®)
Performed: Processed: Sun-Sat Assayed: Mon, Wed, Fri Reported: 1-4 days |
| Specimen Required: | |
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Collect: Sputum, bronchoalveolar lavage (BAL), pleural fluid or other respiratory specimens in a sterile, leak-proof container. Respiratory specimen processed by NaOH-NALC digestion. Unprocessed specimen is preferred. Source of specimen is required.
Transport: For unprocessed specimens: Submit 10-15 mL unprocessed respiratory specimen in a sterile leak-proof container at 2-8°C. Place each specimen in an individual sealed bag. (Min: 1 mL unprocessed specimen). For processed specimens: Submit 5-10 mL processed respiratory specimen in a sterile leak-proof container at 2-8°C. Place each specimen in an individual sealed bag. (Min: 1 mL processed specimen) Identify processed specimens with method used for digestion. For processed specimen smear results must be provided. Submit specimen according to Biological Substance, Category B, shipping guidelines. Pediatric Collection/Transport: Submit specimen according to Biological Substance, Category B, shipping guidelines. Remarks: Collection of early-morning specimens of sputum on each of three consecutive days is optimum. Unacceptable Conditions: Bloody specimens, leaking containers, and lung tissue. Alpha-Tec XPR-Plus is inhibitory (see Note below). Stability: Ambient: Unacceptable; Refrigerated: Unprocessed specimen: 1 week; Processed specimen: 3 days; Frozen: 1 week |
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| Reference Interval: |
| Negative |
| Interpretive Data: | |
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The MTD test is specific for, but does not differentiate among, members of the M. tuberculosis complex. M. celatum and M. terrae-like organisms will cross react if present at concentrations higher than 30 CFU/test. However, those species are rare clinical isolates. Specimens with high levels of nontuberculosis mycobacteria (greater than 1,000,000 cells/test) may cause low-level positive MTD results when M. tuberculosis complex is not present. This test is FDA cleared but is not labeled for use with pleural fluid specimens.
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| Note: | |
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Processed respiratory specimens will be accepted if refrigerated less than or equal to 72 hours and smear result is provided. It is preferred to submit unprocessed, refrigerated respiratory specimens for this assay. |
| CPT Code(s): | |
| 87556 |