This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
[{'content': 'The feulgen reaction is used to test \nSelect and explain. \nA. mRNA, B. tRNA, C. DNA, D. rRNA', 'role': 'user'}, {'content': 'Answer: C \nExplanation: *Feulgen stain is a staining technique to detect DNA *In this procedure, the specimen is exposed to warm HCL which causes hydrolysis of DNA to produce aldehyde. Then Schiff reagent is added which reacts with aldehyde to impa red colour.', 'role': 'assistant'}]