Histology, cytology and other related scientific disciplines study the microscopic anatomy of tissues and cells. In order to demonstrate a good tissue and cellular structure visualization, the samples need to be stained in a correct manner. Azure C powder dye is obtained by oxidation of Methylene blue dye. It is a strong metachromatic dye. It is used for staining nuclei and nuclear material, but can also be used for metachromatic staining of mucin and neuroendocrine cells.