Luxol fadt blue stain (LFB) is used to visualize myelin in nerve tissue. Thanks to this staining, it is possible to visualize the myelin and the fatty substance of the brain called white matter which includes the axons of the nerve cells. The LFB coloration thus makes it possible to differentiate the white matter from the gray matter.

Luxol fadt blue staining is based on a simple acid-base reaction. Fast luxol blue is a phthalocyanine dye of sulfonated copper. This dye is soluble in alcohol and is attracted by the bases contained in the phospholipids of myelin. The excess dye is removed with 95% ethanol and then the tissue section is differentiated with lithium carbonate and 70% ethanol until the gray matter is colorless.

This staining is commonly used to identify basic neuronal structures in the brain and spinal cord.