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': 'Separation of proteins based on size is done by: \nSelect and explain. \nA. Affinity chromatography depending on charge, B. SDS-Polyacrylamide gel electrophoresis, C. Ion exchange chromatography, D. High performance liquid chromatography', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. SDS- Polyacrylamide gel electrophoresis', 'role': 'assistant'}]