Staining of acid mucopolysaccharides appearing on and in various cell types by DAPI.

It could be shown that DAPI, a newer fluorochrome (4',6-diamidino-2-phenylindole), is able to stain various types of acid mucopolysaccharides, e.g. heparin and agar mucopolysaccharides. Due to their content of heparin, mast cells and basophil cells could be stained rapidly. Other cells e.g. mononuclear phagocytes and malignant epithelial cells, could be loaded with these acid mucopolysaccharides and subsequently stained by DAPI.