Micro lab Unknown 2

Which tube (s) aren't supposed to be mixed?

Tubes 6 (TSA slant) and 7 (Tryptone Broth - Indol test)

What broth is in Tube 1?

PR glucose broth

What reagent is used for PR glucose broth?

none

What are the expected results for a PR glucose broth with a positive reaction?

yellow and cloudy

What are the expected results for a PR glucose broth with a negative reaction?

red and cloudy

What are ALL the expected results for a durham tube in a PR glucose broth?

Positive: gas bubble in tube

Negative: no gas bubble in tube

What broth is in Tube 2?

PR Lactose broth

What reagent is used for PR Lactose broth?

none

What are the expected results for a PR Lactose broth with a positive reaction?

yellow and cloudy

What are the expected results for a PR Lactose broth with a negative reaction?

red and cloudy

What broth is in Tube 3?

PR Mannitol broth

What reagent is used for PR Mannitol broth?

none

What are the expected results for a PR Mannitol broth with a positive reaction?

yellow and cloudy

What are the expected results for a PR Mannitol broth with a negative reaction?

red and cloudy

What broth is in Tube 4?

Methyl Red Broth

What reagent is used for Methyl Red Broth?

10 drops of methyl red

What are the expected results for a Methyl Red Broth with a positive reaction?

the broth turns red

What are the expected results for a Methyl Red Broth with a negative reaction?

the broth turns/stays a pale yellow color

What broth is in Tube 5?

Voges-Proskauer Test (name of broth wasnt mentioned)

What reagent is used for Voges-Proskauer Test?

10 drops of Barritt's A and 5 drops of Barritt's B

Make sure to mix VERY well.

What are the expected results for a Voges-Proskauer Test with a positive reaction?

the substance in the tube turns red.

What are the expected results for a Voges-Proskauer Test with a negative reaction?

the substance in the tube turns yellow. it's kinda piss colored ngl.

What broth is in Tube 6?

no broth. the medium used instead is TSA

name used on sheet though is: Catalase Test (TSA Slant)

What reagent is used for Catalase Test (TSA Slant)?

a dropperful of hydrogen peroxide (H2O2)

What are the expected results for a Catalase Test with a positive reaction?

bubbling at the top of the TSA medium

What are the expected results for a Catalase Test with a negative reaction?

no bubbling at the top of the TSA medium

What broth is in Tube 7?

Tryptone Broth.

What is the name of the test that is conducted for Tube 7?

the Indole Test.

What reagent is used for the Indole Test (Tryptone Broth)?

10 drops of Kovac's reagent

After adding MAKE SURE NOT TO MIX THE TUBE!!!

What are the expected results for an Indole Test with a positive reaction?

there will be two distinct layers. the top one is thinner and more saturated with color.

The color in question will be red

What are the expected results for an Indole Test with a negative reaction?

there will be two distinct layers. the top one is thinner and more saturated with color.

The color in question will be yellow

What broth is in Tube 8?

Nitrate broth

What reagents are added to Nitrate Broth after incubation?

5 drops of Barritt's A and 5 drops of Sulfanilic Acid

What are the expected results for a Nitrate Broth with a positive reaction?

cloudy and red. (kind of looks like V8)

What are the expected results for a Nitrate Broth with a negative reaction?

veryyyy pale yellow

What broth is in Tube 9?

Urea Broth

What reagents are added to Urea Broth after incubation?

none

What are the expected results for a Urea Broth with a positive reaction?

Bright barbie pink

What are the expected results for a Urea Broth with a negative reaction?

Orange (looks kind of coral in the slides tbh)

What broth is in Tube 10?

Citrate Slant (name of broth/medium isn't explicitly stated)

What reagents are added to Citrate Slant after incubation?

none

What are the expected results for a Citrate Slant with a negative reaction?

dark earthy green (you may need to hold it up to the light in order to distinguish the colors. they are both very dark)

What are the expected results for a Citrate Slant with a positive reaction?

dark saphire blue (you may need to hold it up to the light in order to distinguish the colors. they are both very dark.)

What broth is in Tube 11?

Not a broth but inside the tube is Motility Media.

What reagents are added to Motility Media after incubation?

none

What are the expected results for a Motility Media with a positive reaction?

HAZE of pinkish-red growth away from the stab line

What are the expected results for a Motility Media with a negative reaction?

distinct pinkish-red growth along the stab line

What broth is in Tube 12?

Not a broth. its Triple Sugar Iron Agar Slant (TSI Slant)

How many things are we looking for in the agar after incubation? name them.

1. acidity

2. alkalinity

3. hydrogen sulfide (aka H2S)

What reagents are added to TSI Slan after incubation?

none

How is the TSI slant tube divided? What are these sections called?

it's split into two halves

• The top half is called the slant

• The bottom half is called the butt

What are the expected results for fermentation in the TSI agar? Name the color, what it indicates, and the Symbol used.

The agar will either be one of three colors:

1. Yellow, indicates Acidity, symbol is "A"

2. Red, indicates Alkalinity, symbol is "K"

3. ANY amount of black in the entire area being described, indicates H2S production, sumbol is "H2S positive"

What are the expected results for positive gas production in the agar of a TSI slant?

there will be gas bubbles, cracks, or displacement of your agar (for example your agar might have developed a huge gap/air pocket out of nowhere.)

What are the expected results for negative gas production in the agar of a TSI slant?

there should be no gas bubbles, cracks, or displacement of your agar. the agar should basically be shaped the way it was prior to its incubation.

How many sections do we have to split the TSI tube into to get results form it? what are the names of each section?

its split into two halves:

1. The top half (from the top part of the slant's hypotenuse to the bottom) is called the slant

2. The bottom half (end of hypotenuse to the very bottom) is called the butt

How does the splitting up of the agar in a TSI slant affect the way we denote the reaction(s)?

two halves of agar means your reaction(s) should be in the form of slant/butt

Ex: a yellow slant/red butt should be written as A/K