DIRECT DETECTION FOR NUCLEIC ACID OF M. TUBERCULOSIS COMPLEX – PROBETEC DTB - Test discontinued w.e.f. 01 June 2020

​As for Mycobacterial Culture, except that blood and bone marrow specimens should be collected in sterile screw-capped containers or plain Vacutainer tubes (NOT in Myco-F-Lytic vials) and delivered to the lab immediately. If delay is unavoidable, the sample may be collected in EDTA or citrated tubes, though amplification results may be less consistent.

​Collect in a dedicated container. Do not order non-CTBL tests using the same request form and on the same specimen. Specimens should reach CTBL within 24 hours of collection. If transport delay is unavoidable, store at 4⁰C.

​ProbeTec Assay (BD ProbeTec ET system) using strand displacement amplification (SDA)

​M. tuberculosis complex DNA detected / Not detected / Indeterminate

​2 - 5 working days

​Tuesdays and Fridays

​Reflex Testing: These tests only provide preliminary information for empirical TB management. A reflex AFB culture, including an AFB smear for respiratory samples if the volume is adequate, is also set up for each specimen. These additional tests are chargeable. Written instruction from the doctor is necessary if these are not to be performed.