The advantages of QuantiFERON include the use of undiluted whole blood and the detection and measurement of IFNγ in undiluted plasma samples. QuantiFERON assays are accurate and sensitive in whole blood and undiluted plasma (1).
The use of whole blood in QFN methods makes T cell incubation simple and fast. There is no tedious lymphocyte isolation, washing, counting, diluting, or culturing. Just shake each tube and incubate 16–24 hours. The simple blood incubation allows processing of a very large number of samples. Logistics are very simple and the QFN method allows virtually labor-free incubation at nearly every location. QFN preserves the in vivo cellular and biochemical environment for lymphocyte stimulation, maximizing cellular responses. The technology is designed for clinical screening of large sample numbers, providing the standards, controls, and assay reproducibility needed for clinical diagnosis.(1)
QFT is approved by the FDA as an in vitro diagnostic aid for detection of Mycobacterium tuberculosis infection. It uses a peptide cocktail simulating ESAT-6, CFP-10, and TB7.7(p4) proteins to stimulate cells in heparinized whole blood. Detection of IFNγ by ELISA is used to identify in vitro responses to these peptide antigens that are associated with M. tuberculosis infection. FDA approval notes that QFT is an indirect test for M. tuberculosis infection (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations. QFT Package Inserts can be found at www.QuantiFERON.com.