Van Gieson Stain is used to differentiate between collagen ａnd smooth muscle in tumors ａnd to demonstrate the increase of collagen in diseases. This method combines two or more anionic dyes ａnd rely on differential binding by tissue components. 
      The differentiation is determined by a combination of differences in the relative size of the dye molecules, differences in the physical structure of the tissue, ａnd differences in the amino acid composition of tissue Elements.