Microbiology Lab Test 1

What kind of microscope do we use for this class?

compound light microscope

Microscope: What is the function of the Iris diaphragm

increase or decrease the amount of light

Microscope: how many magnification is the eyepiece?

10x

Microscope: how many microns is the objective lens if it is at 10x?

1500 microns

Microscope: how many microns is the objective lens if it is at 100x?

150 microns

Say you’re on objective lens 10x, and the microbe reaches halfway through the eyepiece, how “big” is the microbe?

750 microns

Microscope: always view bacteria in what objective lens?

100x with oil immersion

Microscope: What is the index of refraction?

when the light bends and scattered lost (from the gap between the slide and the lens)

label :D

1: Spore structure

2: Aerial hyphae

3: Fruiting body

4: Hyphae

What is the cell wall of bacterias contain?

peptidoglycan

Are protozoa prokaryotes are eukaryotes?

eukaryote

What does bacteria use to move?

Flagella

What is the brewer’s yeast called? Scientifically

Saccharomyces cerevisiae

what is this

Bakers’ yeast!

what is this

Penicillium

what is this?

Aspergillus

What does simple stain mean?

1 stain (1 color/dye), any color

Postive simple stains ___?

Negative simple stains __?

microbe

background

3 function for heat fix stain?

1. drys moisture

2. makes it microbe stick to the glass

3. kills the bacteria

For positive simple staining, what stain do you use?

Crystal violet

For negative simple staining, what stain do you use?

Nigrosin Black (remember to not rinse or blot dry) and congo red

Order of gram staining?

1. Crystal violet

2. Iodine

3. Ethanol

4. Safranin

What shape is a cocci

ball shaped

What shape is lower case bacillus

rod

What shape is spirillum

lazy s shaped

What shape is spirochete?

tight spiral

1. What is this bacterium?

2. Shape?

3. What are the little white spots on it?

4. Disease?

1. Bacillus anthracis

2. filamentous (chains)

3. spores

4. anthrax

What are the two type of Bacillus anthracis and which one is more deadly?

1. Cutaneous (skin)

2. Inhalation (lungs; the more deadly one)

a resident inside a human body; can become deadly. What is this?

E coli

food poisoning, typhoid fever. What is this?

Salmonella

What shape is this?

Spirochete

Lyme disease; comes from ticks; causes confusion

Borellia burgdorferi

Has 3 phases, a STD. What is the name of the bacteria

Treponema pallidum; syphilis

It is a filamentous bacteria and a massive producer of antibiotics

Streptomyces griseus

Causes a really bad headache and can be fatal cause death within a day

Neisseria meningitidis (can tell a Neisseria by its 2×2)

A STD, a diploid (2×2) shaped bacteria

Neisseria gonorrhoeae

What is the white thing around this bacteria and its’ function?

Capsule; made of polysaccharides and protects the bacteria and stick to surfaces

What is this? and what disease? What is that thing in blue?

Clostridium tetani; tetanus; spores

Causes severe diarrhea, carried by hurricanes. Name of bacteria and disease?

Vibrio cholerae; Cholera

What is the most common type used agar in micro?

Tryptic Soy Agar

What is a RODAC plate?

replicates the microbe of a surface

label!

1. Pellicle

2. Ring

3. Turbidity

4. Sediment

The more hazy the turbidity, the more ____

growth

top to bottom, label the form of isolated colony

1. spindle

2. punctiform

3. circular

4. irregular

5. rhizoid

6. filamentous

top to bottom, label the elevation of isolated colony

1. effuse

2. flat

3. convex

4. concave

5. umbonate

6. terraced

7. subsurface

top to bottom, label the margin of isolated colony

1. entire

2. undulate

3. serrate

4. filamentous

5. lobate

top to bottom, label the surface of isolated colony

1. smooth

2. contoured

3. radiate

4. concentric

5. rugose

6. granular

7. curled

What does confluent mean?

2 colonies grew over each other

What does TNTC mean?

too numerous to count

For this class, what is countable value do we use?

25-250

What does opaque mean? How about translucent?

You can’t see through the growth; you can see through the growth

you gotta know the dilution, i have no idea what to ask, the amount of 0s, is how many 10^-n you gotta go

For finding Generation Time graph, what goes on the x-axis and y-axis? What graph paper do you use?

x: Time (in mins or hours etc)

y: Cell # __ x 10^n

-semilog paper

what is the generational time between the time at 60 and 90 mins?

30 mins

what is the term of how bacteria grow?

binary fission

What is the answer to this problem:

10^-4 120 cfu

the work:

120 × 10^-4 bac/ml

1.20 × 10^4 bac/ml

1.2 × 10^6 bac/ml (the answer)

What machine is used to measure turbidity?

Spectrophotometer

What does Optical Density test for? What goes on the x-axis and y?

the amount of light absorbed in the tube;

x: cell #

y: OD

What does % transmission light test for? What goes on the x-axis and y?

amount of light that gets through;

x: cell #

y: % trans

Which one is OD graph, and which one is the % trans?

top one is OD, bottom is % trans

According to this graph, which antibiotic worked the best to fighting this bacteria?

the bottom one

What would TSA test for? And what would it look like?

Staph (opaque) and Strep (translucent)

When you add hydrogen peroxide, would staph or strep bubble?

1. Staph = Cat+ bubbles

2. Strep = Cat- no bubbles

Mannitol Salt Agar grows what and stops what?

Grow staph inhibits strep

What are the two types of staph? What color do they turn into on the MSA plate?

Staph epidermis: pink; Staph aureus: gold/yellow

(remember that if its gold/yellow, run coagulase test with rabbit plasma)

With the Chocolate Agar plate, what does it test for after prof do the oxidase test. If it is positive, what color does that bacteria turn to?

testing for the harmless Resident Neisseria; black (candle jar)

What O2 level are Neisseria species?

microaerophillic

Blood Agar test for what?

Streptococcus

(beta, alpha, gamma)

What does Blood Agar with Crystal Violet test for?

grow strep (looks blue/purple), inhibit staph (also in the candle jar)

Which plate would you choose? And why?

The 3rd one, because it is between 25-250 cfu

What type of plate is this, and what is the purple?

Blood Agar Crystal Violet, with strep

What type of plate is this, and what is the green?

Blood Agar; alpha hemolysis

What type of hemolysis

Beta hemolysis

What type of plate and what is the yellow?

Mannitol salt plate; staphylococcus aureus

What kind of stain, + or -, what kind of bacteria?

congo red, -, E coli

What kind of stain, + or -, what kind of bacteria?

Crystal violet, +, E coli

What kind of stain, + or -, what kind of bacteria?

Congo red, -, Micrococcus luteus