Aniline, alcoholic solution is a component of Azan Trichrome kit for staining connective tissues. The kit is used for visualizing musles, collagen fibers, glial cells, glomerular cells, chromatins and erythrocytes of the same section. Azan Trichrome kit contains two acid dyes: Azocarmine G and Aniline Blue counterstain. Azocarmine G is used at the beginning stage of the staining procedure, and Aniline Blue is used at the final stage, after the section is treated with phosphomolybdic acid. In order to achieve high quality staining results, it is necessary to stain the section using Azocarmine G, and then differentiate it progressively using aniline alcoholic solution in order to enable counterstaining of certain structures (such as collagen) of the section.