Gram's crystal violet solution for the Gram s

Flammable Warning Warning Hexamethyl Violet , Vianin , Basic Violet 3 , Gentian violet , Methyl violet 10B , Hexamethyl-p-rosaniline chloride , CI 42555 , 4-[4,4'-Bis(dimethylamino) benzhydrylidene]cyclohexa-2,5-dien-1-ylidene]dimethylammonium chloride , Gentiaverm , Dimethyl((di(4-(dimethylamino)phenyl)methylen)-2,5-cyclohexadien-1-yliden)ammoniumchlorid , Viocid , Methylrosanilide chloride The Gram staining allows a fast differentiation of bacteria in Gram-positive and Gram-negative. The mureine structure of the bacteria walls is the basis of the color affinity. Bacteria will be stained with Gram's crystal violet solution - an aniline dye - in the first step. After the treatment with iod solution (Lugol’s solution), a dye-iod complex will form. During the decolorizing step, this complex stays in the multilayer mureine structures of the Gram-positive bacteria and they will appear blue. Gram-negative bacteria have a monolayer mureine structure only, the dye-iod complex does not stay bound to the cellwall, they will be decolorized . Gram-negative bacteria will be counterstained by safranin solution and appear orange.