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Test ID MTBXS Mycobacterium tuberculosis Complex, Molecular Detection and Rifampin Resistance, PCR, Sputum


Additional Testing Requirements


Mycobacterial culture is required for epidemiological strain typing and growth-based phenotypic antimicrobial susceptibility testing, including definitive rifampin results as well as results for other antimicrobials. If your facility is unable to perform a mycobacterial culture, order CTB / Mycobacteria and Nocardia Culture, Varies concurrently with this test.



Shipping Instructions


Specimen must arrive within 7 days of collection; if received greater than 7 days from collection, the specimen will be rejected.



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.

 

Specimen Type: Sputum (undigested)

Container/Tube: Sterile container

Specimen Volume: 3 mL

Specimen Stability Information: Refrigerated (preferred) 7 days/Ambient 72 hours

Additional Information:

1. If a single specimen is being shared between mycobacterial culture, acid-fast smear, and/or M tuberculosis PCR, a minimum volume of 3 mL for the respiratory specimen is required. Specimen volumes less than indicated may decrease sensitivity of testing.

2. If insufficient volume is submitted, testing will be canceled.

 

Specimen Type: N-acetyl-L-cysteine/sodium hydroxide (NALC/NaOH)-digested sputum

Container/Tube: Sterile container

Specimen Volume: 3 mL

Collection Instructions:

1. Submit digested specimen treated with NALC/NaOH.

2. Clearly indicate on container and order form that specimen is a digested specimen.

Specimen Stability Information: Refrigerated 7 days

Additional Information:

1. If a single specimen is being shared between mycobacterial culture, acid-fast smear, and/or M tuberculosis PCR, a minimum volume of 3 mL for the respiratory specimen is required. Specimen volumes less than indicated may decrease sensitivity of testing.

2. If insufficient volume is submitted, testing will be canceled.


Useful For

Rapid detection of Mycobacterium tuberculosis DNA from respiratory specimens for the diagnosis of pulmonary tuberculosis

 

Presumptive detection of rifampin resistance based on the presence of resistance-associated mutations

Method Name

Real-Time Polymerase Chain Reaction (PCR)

Reporting Name

M tuberculosis/ RIF PCR GeneXpert

Specimen Type

Sputum

Specimen Minimum Volume

1.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Sputum Refrigerated (preferred) 7 days
  Ambient  72 hours

Reference Values

Negative

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

87556

87798

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MTBXS M tuberculosis/ RIF PCR GeneXpert 89371-9

 

Result ID Test Result Name Result LOINC Value
SRCPX Specimen Source 31208-2
MTBRX MTB Complex Result 88874-3
RIFRX MTB Rifampin Resistance Result 89372-7

NY State Approved

Yes

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.