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: Pathology
[{'content': 'Which one of the following stains is specific forAmyloid? \nSelect and explain. \nA. Periodic Acid schif (PAS), B. Alzerian red, C. Congo red, D. Von - Kossa', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. is \'c\' i.e., Congo Red "To differentiate amyloid from other hyaline deposits (eg. Collagen and fibrin), a variety of histochemical techniques are used, of which the most widely used is Congo Red" - Robbins 7\'/e p. 259 Staining for Amyloid Congo red : It is the most widely used specific stain for amyloid. Iodine staining : It is used for unfixed specimen or histological section. Amyloid stains mahogany brown and if sulfuric acid is added, it turns violet. Thioflavin \'T\' and `S\' give secondary immunoflurescence with ultraviolet light. Thioflavin T is more useful for demonstrating juxtalomerular apparatus of the kidney. Metachromatic stains like crystal violet and methyl violet give rose pink appearance. Amyloid is PAS positive.', 'role': 'assistant'}]