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, the samples need to be stained in a correct manner. Eosin B powder dye can be used instead of Eosin Y WS dye in different staining methods. These two dyes are mutually completely interchangeable, but Eosin B provides barely visible bluish hue instead of yellowish provided by Eosin Y. It is often used in Romanowsky staining methods. It is also used as a counterstain to hematoxylin during cytoplasmic staining.