3,7-Bis(dimethylamino)phenothiazin-5-ium chloride trihydrate 7220-79-3 C.I. Basic Blue 9 trihydrate C.I. Basic Blue 9, trihydrate (8CI) Methylene Blue [USAN] Methylene Blue trihydrate Phenothiazin-5-ium, 3,7-bis(dimethylamino)-, chloride, trihydrate