indole test

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Related to indole test: methyl red test, citrate test, urease test

in·dole test

a test used to identify members of the Enterobacteriaceae family and other gram-negative bacilli, based on the ability of the organisms to produce indole from tryptophan.


a compound obtained from coal tar and indigo and produced by decomposition of tryptophan in the intestine, where it contributes to the peculiar odor of feces. It is excreted in the urine in the form of indican. 3-Methyl-indole and L-tryptophan are implicated in causing acute interstitial pneumonia in cattle.

indole alkaloids
include β-carbolines, dimethyl tryptamines, hydroxy methyltryptamines, alstonines.
indole test
a biochemical test for the identification of bacteria, based on the production of indole from tryptophan in the medium provided.
References in periodicals archive ?
curvatus) characterised through molecular characterization was found to be negative for catalase test, indole test (green layer is formed at the top of test tube), nitrate reduction test, citrate test (no blue colour in test tube), methyl red Voges-Proskeur test (no red colour appears in test tube), casein hydrolysis test (not able to produce protease enzyme) and for starch agar test (not able to produce amylase enzyme) (Table 1).
Then indole test was performed to confirm the Coliforms.
5-1 mm in (1-2 mm in dia) dia) Catalase Test Negative Negative Positive Endospore Negative Negative Negative staining Motility Test Non motile Non motile Motile Indole Test Negative Negative Positive Nitrate Test Negative Negative Positive [H.
coli colonies were injected into triple sugar iron and urea agar slants and subjected to the indole test.
The spot indole test was also positive and confirmatory of the identification.
Selected colonies were sub-cultured for purity onto Levine EMB and Columbia 5% sheep blood, and isolates underwent biochemical testing, including the indole test, which with colonial morphology is a presumptive test for Escherichia coli (N=28), plating on differential media (Rainbow Agar) specific for Shiga toxin producing Escherichia coli (N=17), and latex agglutination tests specific for O157 and H7 antigens (N=17) to confirm Escherichia coli O157:H7.
The spot indole test, completed in less than one minute, is a rapid and convenient method for the culture confirmation of H.
The biochemical tests performed were sugar fermentation tests, catalase tests, indole test, methyl red (MR) test, Vogue's Proskauer(VP) test, lactose fermentation, urease production and citrate utilization (38).
Biochemical characterization and identification of the isolated strain of bacteria (Pasturella multocida) showed a positive oxidase, catalase and indole test which confirmed that the death of mice was due to Pasturella multocida.
The biochemical identification tests showed--spot indole test negative; fermentation of glucose, maltose positive; and no fermentation of lactose, sucrose and xylose was seen.