Screen for TB with confidence using QFT-Plus
QuantiFERON-TB Gold Plus (QFT-Plus) is a simple blood test that accurately identifies people infected with M. tuberculosis (MTB), the causative agent of TB (tuberculosis). QFT-Plus is a modern alternative to the 110-year-old tuberculin skin test (TST).The QFT-Plus assay
The QFT-Plus assay is an in-vitro diagnostic laboratory test that aids in the indirect detection of infection with MTB. It uses human whole blood, with patented assay technology based on the measurement of Interferon-gamma (IFN-γ) secreted from stimulated T-cells previously exposed to MTB. It is a straightforward laboratory test that involves the following steps:-
Step 1
Blood collection -
Step 2
Mixing of tubes -
Step 3
Incubation -
Step 4
ELISA -
Step 5
Calculation of results
Training videos – performing QFT-Plus blood collection
TB testing workflow with QFT-Plus blood collection options
Accurate QuantiFERON-TB Gold Plus (QFT-Plus) test results start with proper blood sample handling. Subsequently, incubation of the blood occurs in the tubes for 16 to 24 hours, after which, plasma is harvested and tested for the presence of IFN-γ produced in response to the peptide antigens.
The QFT-Plus test can be performed in either of the following ways, depending on the blood-collection process:
Option 1: Direct blood draw into QFT-Plus blood collection tubes
Collect 1 ml of whole blood directly into each of four QFT-Plus blood collection tube and hold at room temperature for up to 16 hours prior to incubation.
Option 2: Blood draw into a single lithium- or sodium-heparin tube
Draw at least 5 ml of blood into a single blood collection tube containing lithium or sodium heparin as the anticoagulant. Blood drawn into a lithium- or sodium- heparin tube and maintained at room temperature must be transferred to QFT-Plus Blood Collection tubes and incubated within 16 hours from the time of collection.QuantiFERON TB testing workflow options
Laboratory resources