The staining of mucopolysaccharides with gallocyanin and metal mordants

Summary Some salts of tin, titanium, zirconium, hafnium, niobium, tantalum, molybdenum and tungsten can act as mordants which can combine with polysaccharides and their presence can be detected as colored compounds with an acid alcoholic solution of gallocyanin. None of these metals produced color reaction when used alone. Titanium, zirconium, hafnium, niobium, tantalum and tin form a blue gallocyanin color with salivary, laryngeal, bronchial, gastrointestinal, uterine cervical gland mucins, cartilage and rat mast cells. In addition, tin (IV), titanium (IV), hafnium, niobium and tantalum stained Brunner gland bluish violet to a purple. Gallocyanin mordanted with molybdenum and tungsten stained collagen, reticulum and cartilage blue to dark blue. In addition, tungsten stained some elastic fibers a bright red violet. Paneth cells were stained dark blue by niobium, molybdenum and acidified titanium potassium oxalate. Molybdenum could be extracted by alkalis and titanium by strong acids after tissues have been mordanted. Methylation prior to mordanting inhibits staining of the mucosubstances by titanium. Sulfation enhances staining reactions by titanium and molybdenum.