Malachite Green (chloride) (Synonyms: Basic Green 4, C.I. 4200, C.I. 42000)

Malachite green is a triphenylmethane dye.¹ It inhibits the proliferation of HEp-2 human larynx cells (IC₅₀ = 2.06 µM). Malachite green is cytotoxic to HEp-2 cells and Caco-2 human colorectal adenocarcinoma cells (IC₅₀s = 2.03 and 13.8 µM, respectively). It reduces fungal infection in, and increases hatching rates of, rainbow trout eggs when used at a concentration of 2 µg/ml for 60 minutes twice a week.² Malachite green has been used as a biochemical indicator dye for titrations, pH indicators, and counterstains in histology applications.^3,4,5 Formulations containing malachite green have been used in the textile and pigment industries as dyes.

1.Stammati, A., Nebbia, C., De Angelis, I., et al.Effects of malachite green (MG) and its major metabolite, leucomalachite green (LMG), in two human cell linesToxicol. In Vitro19(7)853-858(2005) 2.Kitancharoen, N., Yamamoto, A., and Hatai, K.Effects of sodium chloride, hydrogen peroxide and malachite green on fungal infection in rainbow trout eggsBiocontrol Sci.3(2)113-115(1998) 3.Tuthill, S.M., Kolling, O.W., and Roberts, K.H.Photometric and visual titration of certain alkaloids in glacial acetic acid using malachite green as indicatorAnal. Chem.32(12)1678-1681(1960) 4.Decnop-Weever, L.G., and Kraak, J.C.Determination of sulphite in wines by gas-diffusion flow injection analysis utilizing spectrophotometric pH-detectionAnalytica Chimica Acta337125-131(1997) 5.Dutton, R.J., Bitton, G., and Koopman, B.Malachite green-INT (MINT) method for determining active bacteria in sewageAppl. Environ. Microbiol.46(6)1263-1267(1983)