QuantiFERON-TB Gold Plus (QFT-Plus)

QFT-Plus is an IFNγ release assay, commonly known as an IGRA, and measures the cell-mediated immune response to specific TB antigens in whole blood. The test employs standard phlebotomy procedures using whole blood to make sample collection easy and fast. Sample incubation can occur on-site or at the testing laboratory, providing your practice with complete flexibility and convenience. Patients may be tested in a single patient visit, with objective results.

QuantiFERON is a powerful Premolecular diagnostic technology that delivers results with high sensitivity, enabling the detection of M. tuberculosis infection even in early or latent stages. The QFT-Plus test employs a peptide cocktail simulating ESAT-6 and CFP-10 proteins to stimulate cells in heparinized whole blood. Detection of IFN-γ by ELISA is used to identify in vitro responses to these peptide antigens, which are associated with M. tuberculosis infection. Premolecular Diagnostics that employ QuantiFERON technology, like QFT-Plus, are able to detect infection at an earlier stage than is possible with DNA- and RNA-based molecular diagnostics.

1. Collect whole blood, using one of two options:
   Direct draw: 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.
   Single lithium-heparin tube: Draw at least 5 ml of blood into a single blood collection tube containing lithium-heparin as the anticoagulant. Blood collected into a single lithium-heparin tube may be stored at room temperature or refrigerated for up to 53 hours prior to transfer to QFT-Plus tubes and incubation.
   Note: QFT-Plus has 4 blood collection tubes: Nil, TB1, TB2, and Mitogen. Collect 1 ml of whole blood into each tube.
2. Incubate for 16 to 24 hours at 37°C.
3. Detect released IFNγ in harvested plasma by ELISA.
4. Analyze results using QFT-Plus Analysis Software.

Refer to the Package Insert for detailed instructions for use.