Malachite green result. Numerous niche applications exploit the intense color of MG. It is used as a biological stain for microscopic analysis of cell biology and tissue samples. In the Gimenez staining method, basic fuchsin stains bacteria red or magenta, and malachite green is used as a blue-green counterstain. Malachite green is also used in endospore staining, since it can directly stain endospores within bacterial cells; here a safranin counterstain is often used. Malachite green can also be used as a saturable absorber in dye lasers, or as a pH indicator between pH 0.2–1.8. However, this use is relatively rare. Leuco-malachite green
Italian submarine Malachite Crete, "Malachite" sighted a British cruiser escorted by a destroyer. She launched two torpedoes at the target, but they both missed her by the stern. From 3 to 14 July 1941 she patrolled north of Ras Azzaz. At 20:00 on July 3 "Malachite" sighted a large cruiser (possibly ) escorted by two destroyers, and immediately launched a torpedo. There was an explosion heard, but there is no reports of this attack in British post-war documents, although some believe an escort was hit. From September 25 to October 5 1941 she patrolled off Ras Aamer. From January 20 to 27, 1942