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: Microbiology
[{'content': 'Southern blotting is used for: \nSelect and explain. \nA. RNA, B. DNA, C. Protein, D. Antibody', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. b. DNA', 'role': 'assistant'}]