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: Biochemistry
[{'content': 'Severe destruction of DNA can be tested by: \nSelect and explain. \nA. ELISA, B. PCR, C. STR, D. Western blot', 'role': 'user'}, {'content': 'Answer: B \nExplanation: PCR is an in vitro method for amplifying a selected DNA sequence that does not rely on the biologic (in vivo) cloning method.\xa0\nPCR permits the synthesis of millions of copies of a specific nucleotide sequence in a few hours.\xa0\nIt can amplify the sequence, even when the targeted sequence makes up less than one part in a million of the total initial sample.\xa0\nThe method can be used to amplify DNA sequences from any source, including viral, bacterial, plant, or animal.\n\nKey concept:\nPolymerase chain reaction can even find cases with severe destruction of DNA.\xa0\nRef : Lippincott’s illustrated reviews for biochemistry , 7th edition.', 'role': 'assistant'}]