Merck, 67309-100ML-F, Kovac′s reagent for indoles

General description
Kovac′s reagent is prepared by mixing p-dimethylaminobenzaldehyde, isoamyl alcohol and concentrated hydrochloric acid. For identification of an organism, the formation of Indole from a tryptophan substrate is a useful diagnostic tool. Indole production is a crucial test in identification of Escherichia coli. After incubation, adding the reagent will help in determination if Indole that has been produced. The reagent turns red when reacts with Indole.
Application
In the presence of oxygen, some bacteria, like E.coli, are able to split tryptophan into indole and alpha-aminopropionic acid. This reagent is for detecting the indole and identify the indole-positive and indole-negative microorganisms.
Kovac′s reagent may be used for spot test for determination of indole by saturating filter paper with the reagent. It may also be used for initial spot test for determination of indole followed by quantification by spectrophotometric assay and HPLC-UV/Vis-MS/MS methods.