The procedure for Congo red staining involves several steps:
1. Preparation of Tissue Sections: Tissue samples are fixed, usually in formalin, and then embedded in paraffin. Thin sections are cut from the paraffin blocks. 2. Deparaffinization and Hydration: The sections are deparaffinized using xylene and then rehydrated through a series of graded alcohol solutions. 3. Staining: The sections are stained with Congo red solution, typically for about 20 minutes. 4. Differentiation: The stained sections are differentiated in an alkaline alcohol solution to remove excess dye. 5. Counterstaining: Hematoxylin is often used as a counterstain to provide contrast and allow better visualization of tissue morphology. 6. Dehydration and Mounting: The sections are then dehydrated, cleared, and mounted for examination under a microscope.
