For identification of an organism, the formation of indole from a tryptophan substrate is a useful diagnostic tool. When indole is combined with kovac s reagent which contains hydrochloric acid and pdimethylaminobenzaldehyde in amyl alcohol the solution turns from yellow to cherry red. Nfpa rating health 3 fire 3 reactivity 1 section 4 first aid measures inhalation. Kovacs reagent is a biochemical reagent consisting of isoamyl alcohol, paradimethylaminobenzaldehyde dmab, and concentrated hydrochloric acid. It is used for the diagnostical indole test, to determine the ability of the organism to split indole from the amino acid tryptophan. Do not ingest, inhale, or allow to come into contact with skin. Remel kovacs indole reagent thermo fisher scientific. Kovac s indole reagent r008 intended use for detection of presence of indole produced by microorganisms due to tryptophan deamination. When the inoculum was overlaid with mineral oil, kovac reagent detected only 80 of 108 74. Because amyl alcohol is not water soluble, the red coloration will form in an oily layer at the top of the broth in the spot test, indole combines, in the filter paper matrix, at an acid ph with p. Indole production is a crucial test in identification of escherichia coli. It is to be used only by adequately trained and qualified laboratory personnel. Thermo scientific remel kovacs indole reagent is for determination of the ability of microorganisms, primarily enterobacteriaceae, to split indole from the tryptophan molecule.