Spot Indole Test- Objective, Principle, Procedure, Results and Limitations

Result Interpretation of Spot Indole Test

Objective of Spot Indole Test To determine the ability of organism for the production of indole by the action of tryptophanase enzyme. Principle of Spot Indole Test Intracellular enzyme tryptophanase mediate the production of indole by hydrolytic activity against amino acid Tryptophan. Bacteria that produce the enzyme tryptophanase are able to degrade the amino acid tryptophan into pyruvic acid, ammonia, and indole.  Indole is detected by its ability to combine with certain aldehydes to form a colored compound. For indole-positive bacteria the … Read more