Methyl red sodium salt

: 4-Dimethylaminoazobenzene-2'-carboxylic acid sodium salt, Acid Red 2

: M 2229

: 845-10-3

: C₁₅H₁₄N₃NaO₂

: 291.28

: Methyl Red sodium salt is the sodium salt of Methyl Red. Methyl red is an indicator dye that turns red in acidic solutions. It is a pH indicator, turning red under pH 4.4, yellow over pH 6.2, and orange in between those values. It is used in microbiology in the Voges-Proskauer test to identify bacteria that produce stable acids through mixed acid fermentation of glucose. Methyl-red positive bacteria include Proteus vulgaris and Escherichia coli. Methyl-red negative bacteria include Enterobacter aerogenes and Serratia marcescens.

: M 2229 (OTTO) Methyl red sodium salt Cas 845-10-3 - used for pH detection.