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. 2023 Dec 6;21:159. doi: 10.1186/s43141-023-00615-5

Table 1.

Test information and results

Test Purpose of the test Validation of the result
Positive Negative
Indole test Screen for the organism that degrades tryptophan and produces indole Cherry red ring formation Yellow/no ring formation
Methyl red Detects if the organism performs mixed acid fermentation Red Yellow
Voges Proskauer Detects the presence of acetoin within the metabolic pathway Red/purple color No color
Citrate utilization Screen for the organism that uses citrate as carbon and energy source Blue Green
Catalase Used for the detection of enzyme catalase Effervescence No effervescence
Coagulase Used for the detection of protein coagulase Clot formation No clot
Oxidase Assay for the presence of cytochrome oxidase Purple Yellow/no color
Urease To test the ability of microbe that degrades urea Pink Yellow
Triple sugar iron agar Determination of carbohydrate fermentation and H2S production Pink with gas Yellow
Blood hemolysis Test for the ability of organism that produces haemolysin Growth seen No growth
Starch hydrolysis Test for the ability of organism that hydrolyses starch Blue with zone of inhibition No zone
Organic acid production Detection of microbe if it produces any organic acid as an intermediate Thick white colony growth Pale /transparent growth