INDOLtest is a drop test, which is designed for rapid (5 min) determination of indole that represents a degradation product of bacterial metabolism of tryptophan. It is intended for fast presumptive determination of E. coli strains, screening differentiation between indole-positive and indole-negative bacterial genera as well as a required additional test of certain identification kits. The principle of the test is hydrolysis of tryptophan to indole, pyruvate and ammonia. Indole reacts with the substrate that forms a part of the diagnostic zone of INDOLtest, p – dimethylaminocinnamaldehyde (DMACA), while producing a blue-green compound.
INDOLtest represents the most sensitive routine method to prove the presence of bacterial tryptophanase
- The detection limit is 3 μg/L of indole
- Grown bacteria on blood agar or medium, which contain tryptophan is necessary
- Each kit of INDOLtest contains a vial of 10ml of solution, i.e. 140 determinations in total
