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. Auramine O powder dye is used in various staining methods in microscopy. It is used in clinical microbiology and histology for detecting tuberculosis Mycobacteria and other acid-fast bacteria. Staining using Auramine O is a fluorescent method of visualizing acid-fast bacteria. Mycobacteria are difficult to stain due to the high amount of lipids and wax in their cellular membranes. When stained using Auramine O dye, acid-fast mycobacteria retain the dye even when exposed to strong destaining solutions, such as HCl-ethanol.