Triple Sugar Iron (TSI) Test Interpretations and Medium Composition

Vocabulary flashcards covering the biochemical interpretations, slant/base observations, and carbohydrate concentrations of Triple Sugar Iron (TSI) agar.

TSI Result Reading Format

The standard reading convention where the result is evaluated and recorded as slant/base.

Red/Yellow (TSI Result)

Glucose fermentation only; peptone catabolized.

Yellow/Yellow (TSI Result)

Glucose and lactose and/or sucrose fermentation.

Red/Red (TSI Result)

No fermentation; peptone catabolized.

Yellow/Yellow, with bubbles (TSI Result)

Glucose and lactose and/or sucrose fermentation; gas produced.

Red/Yellow, with bubbles (TSI Result)

Glucose fermentation only; gas produced.

Red/Yellow, with bubbles and black precipitate (TSI Result)

Glucose fermentation only; gas produced; $H_2S$ produced.

Yellow/Yellow, with black precipitate (TSI Result)

Glucose and lactose and/or sucrose fermentation; $H_2S$ produced.

Yellow/Yellow, with bubbles and black precipitate (TSI Result)

Glucose and lactose and/or sucrose fermentation; gas produced; $H_2S$ produced.

Black Precipitate (TSI)

Indicates that $H_2S$ has been produced.

Bubbles (TSI)

Indicates that gas has been produced.

Glucose (TSI Medium Concentration)

$$0.1\%$$

Sucrose (TSI Medium Concentration)

$$1.0\%$$

Lactose (TSI Medium Concentration)

$$1.0\%$$