A Service of the Hamilton Regional Laboratory
Laboratory Test Information
Committed to Quality
The HRLMP is committed to providing high quality laboratory results for our clients.
As one of the largest integrated laboratory medicine programs in Canada we strive to produce the right results the first time on every sample we receive.
Test Name:
M. tuberculosis PCR
Alternate Name(s): MTB, GeneXpert MTB Test, TB, AFB, acid fast bacilli, tuberculosis
Cepheid GeneXpert
Requisition Form: Download requisition form for: R_708112 (2025-12-09) - LRC Microbiology Requisition - Update - Fillable.pdf
Specimen Requirement: Minimum volume required as 3 mL.
Collect in sterile container.
Send to lab ASAP.
Only specimens from NEW, previously untreated, suspected cases of tuberculosis will be tested.
Specimen Handling Instructions:
Maintain specimen at 4ºC and transport ASAP. Transport at 2-8ºC.
Critical Value: "Mycobacterium tuberculosis detected by PCR"
Turnaround Time: testing is done Mon. to Fri. 0700 to 1500 hrs
Interpretive Comments:
ear47mtete|20504125C0E0|LRCTEST_background|InterpretiveComments|Comments|0xffff03b801000000bb00000001001f00
This test is for use on specimens from new, previously untreated, suspected TB cases only. A positive test result does not necessarily indicate the presence of viable organisms.
Additional Information: Regardless of the Cepheid result, the specimen will be submitted to the Ontario Public Health Laboratory for Culture.

LIS Mnemonic: Meditech: not orderable on wards

Downtime requisition requesting the test as ordered by Infection Prevention and Control or a Microbiologist.

Turnaround time- STAT/Critical - Consult Microbiologist on call.
Method of Analysis: Cepheid GeneXpert MTB/RIF PCR
Test was Last Updated: 12/9/2025
Testing Laboratory: Bacteriology
Testing Site: HGH