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neutral red
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Neutral red

Neutral red

Neutral red


Methyl red (2-(N,N-dimethyl-4-aminophenyl) azobenzenecarboxylic acid), also called C.I. Acid Red 2, is an indicator dye that turns red in acidic solutions. It is an azo dye, and is a dark red crystalline powder. Methyl red is a pH indicator; it is red in pH under 4.4, yellow in pH over 6.2, and orange in between, with a pKa of 5.1. Murexide and methyl red are investigated as promising enhancers of sonochemical destruction of chlorinated hydrocarbon pollutants.Methyl red is classed by the IARC in group 3 - unclassified as to carcinogenic potential in humans.
Synonym: 2-(4-Dimethylaminophenylazo)benzoic acid, 4-Dimethylaminoazobenzene-2′-carboxylic acid, Acid Red 2

Grade:AR Grade

Purity:99% min

CAS Number :493-52-7

EC Number :209-035-8

Molecular Formula:C15H17ClN4

Technical Requirements:


Neutral red

Appearance Red-brown or Purple Crystal Powder
PH Range  4.5 - 6.2, red to yellow
Ignition Residue (w/%) 0.2% max
Loss on Drying (w/%) 1.0% max
Solubility in Ethanol Qualified


In microbiology, it is used in the MacConkey agar to differentiate bacteria for lactose fermentation.
Neutral red can be used as a vital stain. Live cells incorporate neutral red into their lysosomes. As cells begin to die, their ability to incorporate neutral red diminishes. Thus, loss of neutral red uptake corresponds to loss of cell viability.
It is also used to stain cell cultures for plate titration of viruses.
Neutral red is added to some growth media for bacterial and cell cultures. It usually is available as a chloride salt.
Neutral red acts as a pH indicator, changing from red to yellow between pH 6.8 and 8.0.
Useful as an indicator for preparing neutral red paper, and as a biological stain.

Packing:25g/bottle or according to your requirement.

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