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  • 67309 - Kovac’s reagent for indoles

67309 Millipore

Kovac’s reagent for indoles

for microbiology

Synonym: 4-(Dimethylamino)benzaldehyde solution

  • CAS Number 100-10-7

  • Empirical Formula (Hill Notation) C9H11NO

  • Molecular Weight 149.19

  •  Beilstein/REAXYS Number 4132845

  •  MDL number MFCD00003381

  •  PubChem Substance ID 329760541

  •  NACRES NA.85



Related Categories Aldehydes, Biochemical Reagents for Identification, Building Blocks, C9, Carbonyl Compounds,
grade   for microbiology
shelf life   limited shelf life, expiry date on the label
composition   4-(dimethlyamino)benzaldehyde, 50 g/L
  hydrochloric acid, 240 g/L
  isoamylic alcohol, 710 g/L
application(s)   microbiology: suitable (microbial identification)
Featured Industry   Agriculture
Clinical Testing
Food and Beverages
storage temp.   2-8°C
suitability   Escherichia coli
SMILES string   [H]C(=O)c1ccc(cc1)N(C)C
InChI   1S/C9H11NO/c1-10(2)9-5-3-8(7-11)4-6-9/h3-7H,1-2H3


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.


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.

Safety & Documentation

Safety Information

Signal word 
Hazard statements 
Target organs 
Respiratory system
UN 2920 3(8) / PGII
WGK Germany 


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