Incubation of MGIT 960 DST Sets

Incubation of MGIT DST tubes

1. Tighten the caps and mix the inoculated broth well by gently inverting the tube several times.

2. Susceptibility test "Set Carriers" are provided in different numbers of drug combinations. For a routine SIRE test with critical concentration, a Set Carrier of

   five tubes is used. Place labelled tubes in the correct sequence in the set carrier (GC, STR, INH, RIF, EMB).

3. Enter the susceptibility set carrier into the BACTEC MGIT 960 instrument using the susceptibility test set entry feature. Ensure that the order of the tubes in the AST Set Carrier conforms to Set Carrier definitions. For example, GC, STR, INH, RIF, and EMB for the SIRE standard testing.

4. To check the inoculum's purity, streak the test culture suspension onto a blood agar plate. If blood agar is not available, use chocolate agar or BHI agar. Incubate at 37 ºC ± 1ºC for 48 hours and check for any growth. If growth appears, do not set up the susceptibility test. It may be important to establish the purity of the culture before setting up a susceptibility test, particularly if contamination is suspected.

Resource

Mycobacteriology Laboratory Manual 

  Assessment