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. Sudan Black B is a lipophilic diazo dye, very similar to Sudan III that stains lipids, triglycerides and lipoproteins. It is primarily used in the Sudan Black B lipid staining method that stains several kinds of lipids of frozen histology sections, including neutral fats, phospholipids, and sterols. It is also used in hematology as a substitution for myeloperoxidase staining for the demonstration of neutrophil granulocytes in blood smears and bone marrow smears.