| A | B |
|---|
| Methyl Red | Detects a pH change a postive rxn turns red upon the addition of a pH indicator (pH< 4.5) |
| Voges-Proskauer | a red color develops upon the addition of chemicals that detect acetoin |
| Carbohydrate fermentation (TSI)(Durham tube) | include dextrose, lactose, sucrose |
| Durham tube | pH indicator for the production of acid will turn yellow at a pH < 6; if gas is present there will be air bubbles in the tube |
| TSI (triple sugar iron) | yellow color means acid; red color means alkaline; black means H2S; splitting of the agar or lifting it shows gas production |
| SIM | indole is tested by adding 5 drops of Kovac's reagent if it turns red it is positive; sulfur is positive if there is a black color |
| Citrate | checks for the prescence of citrate permease; a pH indicator is used if the slant turns blue it is positive |
| Urea | detects the prescence of urease/ a pink to red color is a positive result(color change is due to a pH indiactor) |
| Catalase | detects the activity of the enzyme catalase by breaking down hyd. perox. and producing bubbles |
| Oxidase | ability of bacteria to produce cytochrome oxidase (C); a dark color develops upon the addition of a specific regent |
| coagulase | detect the enzyme coagulase; that clots blood; the reagent will turn solid and cloudy |
| Gelatin | detect the prescence of gelatinase by the solid gelatin being converted to liquid |
