Staining solution reagent Congo Red

for histologyfor cytology

Minimum number of tests that can be performed 100 Completion time 35 minutes Shelf life 2 years Storage conditions 15-25°C Additional equipment Not required Application Method for highlighting amyloid on tissue sections Result Amyloid substance brick red and birefringent in polarized light Nuclei blue Product for the preparation of cyto-histological samples for optical microscopy. Method to show amyloid in tissue sections. PRINCIPLE This is an empirical method. It is still doubtful whether the formation of the link between amyloid and dye is due to proteins or to glycan in amyloid, or even to both. On the contrary, it is certain that amyloid stained with Congo red displays a marked birefringence in polarized light. From this anisotropy, it has been inferred that amyloid may have an intrinsic molecular organization that is emphasized by Congo red. According to Wirchow and Puchtler, amyloid is the only component in human tissues whose histochemical characteristics can be compared to those of cellulose; therefore, it has been supposed that dye and amyloid are linked by hydrogen bonds, just as it happens with the link between cellulose and Congo red.