M 2095 (OTTO) Methyl green Cas 7114-03-6 - used as a tracking dye in acid buffers for electrophoresis. M 2095 (OTTO) Methyl green Cas 7114-03-6 - used as a tracking dye in acid buffers for electrophoresis. It helps differentiate bacteria and is also a tissue stain for nucleoli and mitochondria in tissues. M 2095 (OTTO) Methyl green Cas 7114-03-6 - used for microscopical staining.