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': 'Protein purification and separation can be done by all, EXCEPT: \nSelect and explain. \nA. Chromatography, B. Dialysis, C. Electrophoresis, D. Densitometry', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Densitometry is the procedure which is used to measure the quantity of the protein. Protein purification and separation can be done by the following methods: Chromatography Dialysis Electrophoresis Centrifugation Precipitation', 'role': 'assistant'}]