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. Fast Green F.C.F. dye is used for staining connective tissues and as a counterstain in methods that result in dark blue, purple and red-stained structures. It is remarkably well soluble in water but much less in alcoholic solutions. Fast Green F.C.F. is used in several trichrome methods, such as methods acc. to Gomori or Masson. It is used as a substitute for Light Green SF dye in Papanicolaou staining methods and in histochemical staining.