This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'The development of a color reaction is indicative of a positive result in which of the following assay? \nSelect and explain. \nA. Immunofluorescence, B. Flow cytometry, C. Radioimmunoassay, D. Enzyme- linked immunosorbent assay', 'role': 'user'}, {'content': "Answer: D \nExplanation: ELISA is used routinely for screening patient sera for many different antibodies . Types :- 1. Indirect ELISA - uses color reaction. 2. Sandwhich ELISA - home pregnancy test's 3. Competitive ELISA-> ability to give results for cruder or samples. -Uses Enzyme linked Antigen rather than Enzyme linkedAntibody. -For detection of HIV Antibody.", 'role': 'assistant'}]