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. Amido Black 10B is an anionic, hydrophilic diazo dye. At first it was used as a component of Van Gieson trichrome dyes for staining collagen and reticulin, as well as hemoglobin. Today it is also used for quantification of protein in tissue sections. It may be used as a nuclear dye in cytology and histology. In biomedicine it is used for detecting protein, i.e. in milk, as well as for staining proteins in gel electrophoresis, but also on polymer membranes.