This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
[{'content': "All of the following are used in Gram's staining except? \nSelect and explain. \nA. Iodine, B. Alcohol, C. Congo red, D. Crystal violet", 'role': 'user'}, {'content': "Answer: C \nExplanation: GRAM STAINING 1)Primary staining with a pararosaniline dye such as crystal violet, methyl violet, or gentian violet 2)Application of a dilute solution of iodine 3)Decolourisation with an inorganic solvent such as ethanol, acetone, or aniline 4)Counterstaining with a dye of contrasting color such as carbon fuchsin, safranine or neutral red Congo Red: It is an organic dye, an azo dye mainly used in the diagnosis of amyloidosis REF:Ananthanarayan & Panicker's Textbook of Microbiology 9th Edition pg no: 13", 'role': 'assistant'}]