Luxol fast blue (LFB) stains identify myelin in nervous tissue. LFB is a sulfonated copper phthalocyanine dye and is the alcohol-soluble counterpart to alcian blue, which is water-soluble. In the LFB staining method, lipoproteins within the myelin are responsible for the staining reaction. The staining mechanism of the LFB method is that of an acid-base reaction. The lipoprotein base replaces the base of the LFB dye, resulting in a dark blue precipitate. The excess dye is removed with 95% ethanol. The tissue section is then differentiated in lithium carbonate and 70% ethanol until the gray matter and white matter are distinguished and sharply contrasted. The white matter will be blue to blue-green.
The image demonstrates a loss of myelinated fibers at the basis pontis in the brainstem.
