This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'Southern blot is used to visualize \nSelect and explain. \nA. RNA, B. DNA, C. Protein, D. Antibody', 'role': 'user'}, {'content': 'Answer: B \nExplanation: A Southern blot is a method used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization. Ref-D.M.Vasudevan 7/e p546', 'role': 'assistant'}]