Inoculum Preparation for Immunochromatographic Test SD Bioline Assay/Capillia/TBcID

Specimen preparation and subsequent steps must be performed in a BSC using full PPE. 

From positive MGIT tubes:

1. Ideally, test AFB smear-positive MGIT tubes within 5 days of instrument positivity. 

2.  Vortex the tightly capped MGIT tube for 30 seconds to ensure the suspension is well-mixed.

From positive LJ slants:

1.  Test 2 to 4-week-old growth. 

2.  Add 200μL of TBC ID extraction buffer or Capilia extraction buffer to a sterile cryovial. 

3.  Using a sterile 10 μL loop, scrape a loopful of several colonies and mix with buffer, avoiding any solid medium and/or contaminants present. 

4.  Vortex the cryovial for 30 seconds to create a uniform suspension.

Further steps are the same for both :

1.  Place 100μL of the specimen, either MGIT culture or bacterial suspension from LJ slant, into the specimen well of the test device. Change pipette tips between specimens. 

2.  Start timer for 15 minutes.

3.  Examine the reading area of the test device after 15 minutes and record the test results. Do not interpret the test after 60 minutes.

   Resource

   GLI Mycobacteriology Manual

   Assessment