Microbiolgy Lab Exam 1

Front 1

An ordinary magnifying glass.

Back 1

Simple Microscope

Front 2

Two simples lenses arranged one in front of the other so that the second magnifies the image produced by the first.

Back 2

Compound Microscope

Front 3

Property of a microscope which allows objectives to be changed without having to refocus.

Back 3

Parfocal

Front 4

the objective (4X....) X the eyepieces 10X

Back 4

total magnification

Front 5

distance between the objective and the object being viewed

Back 5

working distance

Front 6

thickness of a specimen that can be seen in focus at one time.

Back 6

depth of focus

Front 7

the ability of a microscope to distinguish between two closely adjacent points. Measured in in distance units. um

Back 7

resolving power

Front 8

Measure of how much the speed of light is reduced inside a medium such as glass.

Back 8

Refractive index

Front 9

Bacteria -Rod

Back 9

Bacilli

Front 10

Bacteria - Spheres

Back 10

Cocci

Front 11

Bacteria - Spiral

Back 11

Spiral

Front 12

Clear halo around small pink rods, all on a pink background

Back 12

Capsule Stain

Front 13

How should plates be stored and why?

Back 13

Inverted, so that condensation does not drip on specimen.

Front 14

Differences in appearance

Back 14

Colony morphology,

Front 15

Transfer organisms from one location to another without contamination to the original culture

Back 15

Aseptic Technique

Front 16

Aseptic Technique

Back 16

A/Sepis. without contamination

Front 17

Proper aseptic technique minimizes? And to preserve?

Back 17

the chance of infection of the microbiologist is handling a pathogen. Pure culture.

Front 18

Aseptic Technique Steps

Back 18

1. Have your act together
2. Completely flame sterilize the transfer loop.
3. Hold the broth or tube at a 45 degree angle. Do this while holding the lid and the transfer loop.
4. Flame the lip of the test tube.
5. Place your loop into the tube and remove a loopful of culture.
6. Reflame the lip of the test tube and replace the cap.

Front 19

If a culture is on a slant where will the growth be restricted to?

Back 19

To the surface so do not gouge surfances of the slant.

Front 20

Wet Mount Technique

Back 20

1. Use aseptic technique to transfer several loopfuls of broth culture to slide.
2. Add 1 drop of gram's iodine.
3. Cover slip
4. Place slide on microscope.
5. View it
6. Record observations.

Front 21

3 basic staining procedures

Back 21

The Simple Stain
Selective Staining
Differential

Front 22

The simple stain

Back 22

involves the use of a single stain which enables the microorganism to be readily observed.

Front 23

the use of a single stain which enables the microorganism to be readily observed

Back 23

Simple Stain

Front 24

Used to selectively stain specific bacterial structures which would not be visual through simple staining.

Back 24

Selective Stain
Ex. 1. Cell Wall
2. Endospores
3. Flagella
4. Capsules

Front 25

This allows for distinction between different classes of bacteria.

Back 25

Differential Stain
Ex. 1. The Gram Stain
2. The Acid Fast Stain

Front 26

Stains the organism - not the background.

Back 26

Positive Simple Staining

Front 27

Positive Simple Stain Technique

Back 27

1. Aseptic Technique - obtain loopful of culture.
2. Spread drop out as much as possible.
3. Flame Sterilize the loop
4. Let the smear dry
5. Heat fix - do not overheat
6. Cover with methylene blue
7. Rinse after 90 seconds with gently running water.
7. Blot dry with Kimwipe
8. After slide is completely dry examine under microscope.

Front 28

Stains the background. Not the organism.

Back 28

Negative simple stain

Front 29

Negative Simple Stain Technique

Back 29

1. Place a small drop of nigrosin near the end of the slide.
2. Use aseptic technique to obtain loopful of microorganism and mix it with the drop of stain.
3. Spread the drop across the slide using a second slide (same procedure used in blood smear)
4. Allow to air dry. DO NOT HEAT FIX.
5. Examine under high dry and oil immersion

Front 30

The Gram Stain is a

Back 30

differential stain

Front 31

relatively thick cell wall composed of 60-100% peptidoglycan.

Back 31

Gram Positive

Front 32

Cell wall is chemically more complex .
Less peptidoglycan
Second layer exterior to the cell peptidoglycan layer, composed of proteins and lipopolysacharides.

Back 32

Gram Negative

Front 33

SIngle most important staining technique

Back 33

The Gram Stain

Front 34

The Gram Stain Technique

Back 34

1. Make a thin smear and heat fix.
2. Stain Crystal Violet for 1 minute.
3. Wash
4. Cover with Gram's Iodine for 1 minute
5. Wash
6. Drop acetone-alcohol until no more color flows from the smear.
7. Wash
8. Cover with safranin (counterstain 1 minute)
9. Wash with water
10.Blot dry

Front 35

The Color Of The Gram Positive Stain After Each Chemical

Back 35

1. Crystal Violet - Purple
2. Gram's Iodine - Purple
3. Acetone - Alcohol - Purple
4. Safranin - Purple

Front 36

The Color Of The Gram Negative Stain After Each Chemical

Back 36

1. Crystal Violet - Purple
2. Gram's Iodine - Purple
3. Acetone - Alcohol - Colorless
4. Safranin - Red or Pink

Front 37

Bacteria that do not stain well and must be heat fixed to drive in the stain.

Back 37

Acid Fast

Front 38

is a physical property of some bacteria referring to their resistance to decolorization by acids during staining procedures.

Back 38

Acid Fast

Front 39

Acid - Fast Staining Technique

Back 39

1. Make and heat fix smear
2. Flood with carbolfuchsin
3. Gently heat fix over a flame until vapors appear. DO NOT BOIL
4. Allow the slide to cool
5. Decolorize 15seconds with acid-alcohol.
6. Wash with water
5. Apply methylene blue for 1 minute.
6. Wash
7. Blot

Front 40

Acid Fast Organism Colors

Back 40

Carbolfuchsin - Red
Acid - Alcohol - Red
Methylene Blue - Red

Front 41

Non Acid Fast Colors

Back 41

Carbolfuchsin - Red
Acid Alcohol - Colorless
Methylene Blue - Blue

Front 42

A selective stain used to see a dormant, tough, and non-reproductive structure

Back 42

Spore Stain

Front 43

Spore Stain Technique

Back 43

1. Make and heat fix smear
2. Cover the slide with malachite green for one minute.
3. Heat the slide until vapors form but does not boil.
4. Replenish the dye so it does not dry
5. Allow the slide to cool
6. Apply safranin for 30 seconds
7. Wash
8. Blot
9. Observe under microscope

Front 44

Spore Colrs

Back 44

1. Malachite Green - Green
2. Water - Green
3. Green

Front 45

Vegetative Cell Colors

Back 45

1. Malachite Green - Green
2. Water - Colorless
3. Safranin - Red

Front 46

The Cell Wall Stain Technique

Back 46

1. Make smear
2. heat fix
3. Add 3 drops of CP-CL
4. Add one drop of Congo Red
5. Mix the drops with your transfer loop
6. Rinse with water
7. Counterstain for 2 with methylene blue

Front 47

The Cell Wall Stain Colors

Back 47

Cell Walls - red
Remainder of cell - blue

Front 48

The Most Common Method To Obtain Pure Culture

Back 48

Streak Plate

Front 49

Vegetative Cell Colors

Back 49

1. Malachite Green - Green
2. Water - Colorless
3. Safranin - Red

Front 50

The Cell Wall Stain Technique

Back 50

1. Make smear
2. heat fix
3. Add 3 drops of CP-CL
4. Add one drop of Congo Red
5. Mix the drops with your transfer loop
6. Rinse with water
7. Counterstain for 2 with methylene blue

Front 51

The Cell Wall Stain Colors

Back 51

Cell Walls - red
Remainder of cell - blue

Front 52

The Most Common Method To Obtain Pure Culture

Back 52

Streak Plate

Front 53

Method to dilute inoculum across a streak plate

Back 53

mechanically dilute

Front 54

Media used to grow a wide variety

Back 54

General Purpose

Front 55

Used to distinguish or differentiate bacteria

Back 55

Differential Media

Front 56

Contain additional nutrients

Back 56

Enriched Media

Front 57

Heat tolerance is assessed by exposing bacteria to a fixed temperature various times.

Back 57

thermal - death- time

Front 58

determination of the temperature that kills all microorganisms in a fixed time period. Usually 10 minutes.

Back 58

Thermal-death-point

Front 59

Electromagnetic Spectrum includes wavelength we consider light, because they are detectable to the human eye.

Back 59

(400-700 nm)

Front 60

Ultraviolet and germicidal radiation

Back 60

(200 - 300 nm)

Front 61

Ionizing Radiation

Back 61

(less than 200 nm)

Front 62

maximum peak absorption of DNA and maximum emitance of germicidal lamps.

Back 62

(254 nm)

Front 63

Characteristics of good disinfectants

Back 63

1. ability to kill wide variety or microorganisms
2. relatively low toxicity to humans
3. rapid actions
4. good penetrating power
5. soluability in water
6. low cost

Front 64

A measure of antibiotic sensitivity

Back 64

inhibition zone

Front 65

Size of antibiotic sensitivity

Back 65

1. diffusibilty of the anitibiotic through the agar
2. the concentration of the antibiotic
3. the sensitivity of the organism