Kresylecht violet is a dye used in Nissl staining, a histological staining technique for visualizing neurons and their cell bodies in nervous tissue. Nissl staining allows identification and characterization of neurons based on staining of the Nissl substance (a rough endoplasmic reticulum) within the cell bodies.

In Nissl staining, tissue sections are stained in a cresylecht violet solution that selectively stains the Nissl substance. The Nissl substance appears purple under the microscope, clearly revealing the cell bodies of neurons and glial cells. This technique is useful in studying the general organization and morphology of nervous tissue, particularly in identifying different types of neurons and in assessing changes in cellular structure in response to disease or injury.

After staining with cresylecht violet, sections are dehydrated in ascending concentrations of alcohol, clarified in xylene, and finally mounted in appropriate mounting medium to prepare them for microscopic examination. Nissl staining is a fundamental and important technique in neuropathology and neuroanatomical research, as it provides valuable information about the structure and function of neurons and other cells in nervous tissue.