|
|
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Mycobacterium tuberculosis complex DNA detection by PCR
Test Code38215
CPT Codes
87556<br>This test is not available for New York patient testing<br>Limited Access Code
Preferred Specimen
1 cc tissue (fresh or paraffin embedded), or
1 mL fluid (non-blood) from normally sterile sites, or
1 mL broncheoalveolar-lavages (BAL), or
1 mL urine, processed sputa, or gastrointestinal biopsies
1 mL fluid (non-blood) from normally sterile sites, or
1 mL broncheoalveolar-lavages (BAL), or
1 mL urine, processed sputa, or gastrointestinal biopsies
Other Acceptable Specimens
E-swabs • Formalin-fixed paraffin-embedded tissues (FFPE, PET) • Non-blood body fluids collected in Vacutainer tubes without preservative • EDTA (lavender-top) tube • Tubes containing SPS (yellow-top)
Instructions
Testing initiated upon receipt of specimen, Monday-Friday.
Specimens should be collected into a DNA free container labeled with at least two identifiers.
Tissue specimens should be submitted and maintained on dry ice. Please indicate if sputa have been processed prior to submission for testing.
Specimens should be collected into a DNA free container labeled with at least two identifiers.
Tissue specimens should be submitted and maintained on dry ice. Please indicate if sputa have been processed prior to submission for testing.
Transport Temperature
Frozen
Specimen Stability
Tissue/fluid
Room temperature: 6 hours
Refrigerated: 24 hours
Frozen: 60 days
*For fixed tissue (PET blocks/unstained slides/scrolls)
Room temperature: Unrestricted
*Quest unable to do range/used maximum
Room temperature: 6 hours
Refrigerated: 24 hours
Frozen: 60 days
*For fixed tissue (PET blocks/unstained slides/scrolls)
Room temperature: Unrestricted
*Quest unable to do range/used maximum
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Tissues free-floating in formalin; Samples containing SPS, citrate, or heparin; Blood/Serum specimens; Samples collected on swabs (other than E-swabs)
Methodology
DNA extraction, Sequencing, Polymerase Chain Reaction, nucleic acid purification
Setup Schedule
Set up: Mon-Fri; Report available: 2-4 days (preliminary)
Reference Range
See Laboratory Report
Clinical Significance
Although an acid fast smear (AF smear) can provide an important clue to the nature of the causative agent for a patient's disease, a positive result does not necessarily indicate the presence of M. tuberculosis complex (MTBC). The presence of AF Bacillis (AFBs) in clinical specimens can be simply due to the growth of common water contaminants such as M. chelonae and M. fortuitum. On the other hand, a negative smear result also does not rule out the presence of M. tuberculosis complex at low pathogen load. Recent developments in PCR based amplification and detection of organism specific DNA offers an alternative that can be more specific and sensitive than a smear test.
For an accurate detection of the presence of MTBC in clinical specimens, the UWMC Molecular Diagnosis Section utilizes a nested PCR protocol that targets heat shock protein 65 gene (hsp65). Utilization of species-specific fluorescent probes on a real-time PCR platform facilitates rapid and highly sensitive detection of M. tuberculosis complex-specific DNA in clinical specimens.
In many specimens acid fast bacilli can be seen microscopy of tissue sections but are very difficult to grow due to their fastidious nature, or are not viable as a result of antimicrobial therapy. Some specimens may never reveal the presence of a pathogen because of low abundance and/or lack of viability. The use of PCR to detect this DNA extracted directly from clinical specimens facilitates the identification of these pathogens.
For an accurate detection of the presence of MTBC in clinical specimens, the UWMC Molecular Diagnosis Section utilizes a nested PCR protocol that targets heat shock protein 65 gene (hsp65). Utilization of species-specific fluorescent probes on a real-time PCR platform facilitates rapid and highly sensitive detection of M. tuberculosis complex-specific DNA in clinical specimens.
In many specimens acid fast bacilli can be seen microscopy of tissue sections but are very difficult to grow due to their fastidious nature, or are not viable as a result of antimicrobial therapy. Some specimens may never reveal the presence of a pathogen because of low abundance and/or lack of viability. The use of PCR to detect this DNA extracted directly from clinical specimens facilitates the identification of these pathogens.
