Using acid-base chemistry, three dyes are employed to selectively stain muscle, collagen fibers, fibrin, and erythrocytes. Bouin’s solution is used first as a mordant to link the dye to the targeted tissue components. Nuclei are stained with Weigert’s hematoxylin, an iron hematoxylin, which is resistant to decolorization by the subsequent acidic staining solutions. Biebrich scarlet-acid fuchsin solution stains all acidophilic tissue elements such as cytoplasm, muscle, and collagen. Subsequent application of phosphomolybdic/phosphotungstic acid is used as a decolorizer causing the Biebrich scarlet-acid fuchsin to diffuse out of the collagen fibers while leaving the muscle cells red. Application of aniline blue will stain the collagen, after which, 1% acetic acid is applied to differentiate the tissue sections.