Methyl green zinc chloride salt ~85%, Sigma-Aldrich®

Methyl green is a synthetic, triphenylmethane-type cationic dye related to ethyl green mainly used as DNA stain in histochemistry. It possesses aniline rings with different degrees of methylation. The dye binds specifically to the A-T rich regions of the major groove of DNA with the help of two positive charges. Methyl green in combination with pyronin is extensively used to stain RNA and plasma cells in tissue sections and cytologic preparations.

Methyl green is suitable as a nuclear counterstain in enzyme histochemistry, immunostaining, and in situ hybridisation as the bluish-green color will be in contrast with red, purple, brown, and black products of histochemical reactions. It is also suitable as a tracking dye in Acid-polyacrylamide gel electrophoresis to separate gliadins. It has been used in the histochemical staining for the apoptosis examination of kidney tissue and as a nuclear stain for labeling embryos. Material may be a mixture of monobromo-monochloro and dichloro ZnCl₂ salts. Halogen contents listed on label.