Compartment	Reaction	Negative	Positive
1	glucose fermentation	red/orange	yellow
1	gas production	wax not lifted	wax lifted

Remarks: Glucose - Any degree of yellow is positive. Acid end products from glucose fermentation turn the pH indicator from red (alkaline) to yellow (acid).
Remarks: Gas - Positive is a definite and complete separation of the white wax overlay from the surface of the glucose medium. Detects gas from glucose fermentation.

Compartment	Reaction	Negative	Positive
2	lysine decarboxylase activity	yellow	purple

Remarks: Any degree of purple is positive. Alkaline end products from the decarboxylation of lysine changes the pH indicator from pale yellow (acid) to purple (alkaline).

Compartment	Reaction	Negative	Positive
3	ornithine decarboxylase activity	yellow	purple

Remarks: Any degree of purple is positive. Alkaline end products from the decarboxylation of ornithine changes the pH indicator from pale yellow (acid) to purple (alkaline).

Compartment	Reaction	Negative	Positive
4	hydrogen sulfide production	beige	black
4	indole production (done last)	colorless	red

Remarks: Hydrogen sulfide - Only a true black is positive. Reduction of thiosulfate produces hydrogen sulfide which reacts with iron salts to produce black ferric sulfide.
Remarks: Indole - This test is not interpreted until all other compartments have been read. Kovac's Reagent must be added before reading. Indole, produced from the breakdown of tryptophan, reacts with Kovac's reagent turning it red.

Compartment	Reaction	Negative	Positive
5	adonitol fermentation	red	yellow

Remarks: Any degree of yellow is positive. Acid end products from adonitol fermentation turn the pH indicator from red (alkaline) to yellow (acid).

Compartment	Reaction	Negative	Positive
6	lactose fermentation	red	yellow

Remarks: Any degree of yellow is positive. Acid end products from adonitol fermentation turn the pH indicator from red (alkaline) to yellow (acid).

Compartment	Reaction	Negative	Positive
7	arabinose fermentation	red	yellow

Remarks: Any degree of yellow is positive. Acid end products from adonitol fermentation turn the pH indicator from red (alkaline) to yellow (acid).

Compartment	Reaction	Negative	Positive
8	sorbitol fermentation	red	yellow

Remarks: Any degree of yellow is positive. Acid end products from adonitol fermentation turn the pH indicator from red (alkaline) to yellow (acid).

Compartment	Reaction	Negative	Positive
9 (not normally used)	Voges-Proskauer	colorless	red

Remarks: This test is not used unless required later as a confirmatory test. Acetoin produced during the production of butylene glycol from glucose fermentation reacts with the added reagents KOH and alphanaphthol and turns red.

Compartment	Reaction	Negative	Positive
10	dulcitol fermentation	not yellow	yellow
10	phenylalanine deaminase activity	not black/smoky gray	black/smoky gray

Remarks: Dulcitol - Yellow or pale yellow is positive. Any other color is negative. Acid from dulcitol fermentation turns the pH indicator from green (alkaline) to yellow (acid).
Remarks: PA - Pyruvic acid produced from deamination of phenylalanine reacts with ferric salts in the medium turning it black.

Compartment	Reaction	Negative	Positive
11	urea hydrolysis	beige	red/purple

Remarks: Hydrolysis of urea forms ammonia which causes the pH indicator to turn from yellow (acid) to pink, red, or purple (alkaline).

Compartment	Reaction	Negative	Positive
12	citrate utilization	green	blue

Remarks: Any degree of blue is positive. Utilization of citrate produces alkaline products turning the pH indicator from green (acid) to blue (alkaline).

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Microbiology Laboratory Manual by Gary E. Kaiser, PhD, Professor of Microbiology
is licensed under a Creative Commons Attribution 4.0 International License.
Last updated: September, 2017