Malachite green: applications in electron microscopy.

Incorporation of malachite green into a glutaraldehyde fixative results in enhanced staining of a number of cellular elements. Ribosomes and myofilaments exhibit increased electron density, but cell membranes generally are not stained. In certain tissues, lipid inclusions are uniformly and heavily stained. Other populations of lipid droplets exhibit differential affinity for malachite green, facilitating their division into subclasses. In addition to its function as a dye, malachite green has previously been reported to stabilize lipid elements soluble in aqueous glutaraldehyde. Such a component was observed in the stroma of uterine endometrium. The variety of cell components which exhibit increased contrast after preparation with malachite green suggests that this technique may find widespread application in fine structure studies.