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 IFN by ELISA is used to identify in vitro responses to these peptide antigens that are associated with M. tuberculosis infection. 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.