Why does malachite green both stain and sterilise?

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Malachite green is a common spot on seafood these days. What chemical is malachite green and how is it related to malachite? To answer these questions, let’s start with the composition and history of malachite green. Origin of  

Malachite Green 

Malachite Green is a bright green crystal with a metallic luster invented in 1877 by the German organic chemist Hermann Fischer. Its chemical structure consists of three benzene rings attached to  carbon atoms in the nucleus. In contrast,  two hydrogens on different benzene rings are replaced by methylene amine groups, which are classified as  extended dyes of triphenylmethane. The name of this compound is malachite green, but it is simply called “malachite green” because its composition is completely different from  the natural mineral malachite, and its color is similar. Malachite is primarily used in copper smelting and as a pigment, but malachite green has other functions as well. 

Malachite Green Color Development Principle 

Malachite Green is a synthetic organic compound. One mole of benzaldehyde and two molecules of xylolamine are heated in a mixture of concentrated hydrochloric acid  and concentrated to form a latent pigment base, which is oxidized by adding lead peroxide under acidic conditions to convert the pigment base into an alkaline solution. Let it settle. Solved. It belongs to the triphenylmethane series of green dyes. As a common dye, Malachite Green is also  used in the pigment industry. Formally, malachite green refers to the chloride salt [C6H5C(C6H

N(CH3)2)2]Cl, but the term malachite green is used very loosely and usually refers to  colored cations. Anions do not affect  color. The bright blue-green color of the cation comes from the absorption band at 621 nm (absorbance 105 M-1 cm-1). 


Uses of Malachite Green 

Malachite Green was originally used to dye clothing fibers, leather, wool and paper. In addition, the ability to stain cell tissues facilitates observation under a microscope. However, the use of malachite green in aquaculture  expanded from the 1930s, when scientists found that aqueous solutions of malachite green were effective in reducing fungal infections, killing microbes, and preventing wound infections in fish. I’m here. Malachite green is still widely used to treat fish diseases and prevent infections. 

Malachite is also  used as a blue-green counter-dye in some biological experiments. At the time, we were using BenchChem Malachite Green in our experiments. Malachite green was also  used to stain endospores, as it can directly stain the inside of bacterial cells. The specific experimental procedure was to smear the moss with budding spores according to the Gram staining method, blot  with a saturated solution of malachite green  for 10 minutes, and  rinse  with tap water. After rinsing, the moss was re-stained with a 0.5% red solution and examined under a microscope. We found that the spores were green and the bacteria and bacteriophages were slightly red, indicating a pronounced staining effect. 

Malachite Green has also been used as an indicator for pH  0.2 to 1.8, but this application is rare. Malachite green was also  used to detect potential bleeding in the forensic field.

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