This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lab Investigations, Subject name: Microbiology
[{'content': 'Test done for mycobacterium tuberculosis by whole blood is : \nSelect and explain. \nA. BACTEC, B. IGRA, C. GeneXpe, D. Culture', 'role': 'user'}, {'content': 'Answer: B \nExplanation: IGRA is interferon gamma release assay .In this test,we target up with the aificial intake of mycobacterium like ESAT-6,CFP-10,TB-7.7, by adding the sample blood(sensitized ) having T-cells which release interferon gamma and its activity can be measured. It is highly specific and there are no positive results.', 'role': 'assistant'}]