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HelpOrder Code LABMTBT Mycobacterium tuberculosis Complex, Molecular Detection, PCR, Paraffin, Tissue
Useful For
Preferred method for rapid detection of Mycobacterium tuberculosis complex DNA in formalin-fixed, paraffin-embedded tissue specimens
Detecting M tuberculosis complex
This test is not intended for the detection of latent tuberculosis and must not be used as a substitute for tests intended for detection of latent tuberculosis such as the tuberculin skin test or an interferon gamma release assay.
Method Name
Real-Time Polymerase Chain Reaction (PCR)
Reporting Name
MTB complex PCR, FFPESpecimen Type
Tissue, ParaffinAdditional Testing Requirements
When non-fixed specimen is available, a mycobacterial culture on that specimen must always be performed in addition to this test. If your facility is unable to perform mycobacterial culture, order CTB / Mycobacteria and Nocardia Culture, Varies concurrently with this test.
Necessary Information
Specimen source is required.
Specimen Required
The high sensitivity of amplification by polymerase chain reaction requires the specimen to be processed in an environment in which contamination of the specimen by Mycobacterium tuberculosis DNA is unlikely.
Preferred Paraffin-embedded tissue block:
Supplies: Tissue Block Container (T553)
Specimen Type: Formalin-fixed, paraffin-embedded tissue block (FFPE)
Sources: Body tissue
Container/Tube: Tissue block
Collection Instructions: Submit a FFPE tissue block to be cut and returned.
Acceptable Paraffin-embedded tissue block:
Specimen Type: Formalin-fixed, paraffin-embedded tissue block (FFPE)
Sources: Body tissue
Container/Tube: Sterile container for each individual cut section (scroll).
Collection Instructions: Perform microtomy and prepare five separate 10-micron sections. Each section (scroll) must be placed in a separate sterile container for submission.
Specimen Minimum Volume
See Specimen Required.
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Tissue, Paraffin | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
| Any non-formalin-fixed, paraffin-embedded tissue block(FFPE) FFPE slides FFPE body fluids |
 Reject |
Reference Values
Not applicable
Method Description
Following specimen processing, genomic DNA is extracted, and the purified genomic DNA is placed on the LightCycler instrument, which amplifies and monitors, by fluorescence, the development of target nucleotide sequences after each polymerase chain reaction (PCR) cycle. A specific target sequence from a portion of the katG gene from Mycobacterium tuberculosis complex is amplified and the resulting segment is detected by melt-curve analysis using sequence-specific fluorescence resonance energy transfer hybridization probes. The LightCycler PCR assay is a closed PCR system that greatly reduces the potential for false-positive results due to specimen cross-contamination as compared with traditional open-system PCR or other amplification methods like transcription-mediated amplification.(Buckwalter SP, Connelly BJ, Louison LK, et al: Description, validation, and review of a decade of experience with a laboratory-developed PCR test for detection of Mycobacterium tuberculosis complex in pulmonary and extrapulmonary specimens. J Clin Tuberc Other Mycobact Dis. 2022 Nov 12;29:100340. doi: 10.1016/j.jctube.2022.100340)
Day(s) Performed
Monday through Sunday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
87556