Micro Lab Quiz1

Front 1

pg 73, Ch 3 Review

3. label a.

Back 1

a. ocular lens

Front 2

pg 73, Ch 3 Review 3. label b.

Back 2

b. objective lens

Front 3

pg 73, Ch 3 Review 3. label c.

Back 3

c. condenser lenses

Front 4

pg 73, Ch 3 Review 3. label d.

Back 4

d. diaphragm

Front 5

pg 73, Ch 3 Review 3. label e.

Back 5

e. Illuminatoer

Front 6

Magnification of the compound light microscope

10X eyepiece * 4X Objectivelens =

Back 6

40X magnification

Front 7

Magnification of the compound light microscope 10X eyepiece * 10X Objective lens =

Back 7

100X magnification

Front 8

Magnification of the compound light microscope 10X eyepiece * 100X Objective lens =

Back 8

1000X magnification

Front 9

Resolution in a compound light microscope

Back 9

"Resolution" the ability of the lenses to distinguish two points

In a compound microscope, the wavelength of the light waves that illuminate the specimen limits the resolution. The wavelength of visible light ranges from about 400 to 700 nanometers. The best compound microscopes cannot reslove parts of a specimen that are closer together than about 200 nanometers.

Front 10

Parfocaling an a compound light microscope objective lens

Back 10

"Parfocal" refers to objectives that can be changed with minimal or no refocusing.

4X and 10X objective lens' do not have adjustable settings

Front 11

Types of Microscopes

Simple microscope

Back 11

Has only one lens

Front 12

Types of Microscopes

Compound Light microscopy

Back 12

-Uses visible light to observe specimens

-Resolution is the ability of lenses to distinguish two points

-A microscope with a resolving power of 0.4 nm can distinguish between two points greater or equal to 0.4 nm

-Shorter wavelengths of light provide greater resolution

-The refractive index is a measure of the lightbending ability of a medium

-The light may bend in air so much that it misses the small high-magnification lens

-Immersion oil is used to keep light from bending

Front 13

Types of Microscopes

Brightfield Illumination

Back 13

-dark objects are visible against a bright background

-light reflected off the specimen does not enter the objective lens

Front 14

Types of Microscopes

Darkfield Illumination

Back 14

-light objects are visible against a dark background

-light reflected off specimen enters the objective lens

Front 15

Types of Microscopes

Phase-Contrast Microscopy

Back 15

• accentuates diffraction of the light that passes through a specimen
  

Front 16

Types of Microscopes

Fluorescence Microscopy

Back 16

• Uses UV light
• Fluorescent substances absorb UV light and emit visible light
• Cells may be stained with fluorescent dyes (fluorochromes)

Front 17

Types of Microscopes

Electron Microscopy

Back 17

• Uses electrons instead of light
• The shorter wavelength of electrons gives greater resolution

Front 18

Types of Microscopes

Scanning Electron Microscopy (SEM)

Back 18

• An electron gun produces a beam of electrons that scans the surface of a whole specimen
• Secondary electrons emitted from the specimen produce the image

Front 19

The microscope you will use in this lab is called a _____________microscope.

Back 19

The microscope you will use in this lab is called a Brightfield compound microscope.

Front 20

What is the most common differential staining procedure in Microbiology?

Back 20

Gram Stain

Front 21

What is a Gram Stain?

Back 21

• A Gram Stain is a differential stain that allows you to classify bacteria as either Gram+ positive or Gram- negative.
• Useful for initially beginning to ID bacteria based on shape, arrangement and Gram response.

Front 22

What is a Gram + positive stain?

Back 22

• Bluish/purple color
• Staphylococcus,Streptococcus
• Decolorizes slowly and maintain the primary stain
• Gram+ bacteria has a thick Peptidoglycan cell wall
• Tend to be killed by Penicillin and detergents
• Alcohol dehydrates the Peptidoglycan, holds in the crystal violet- remains purple.

Front 23

What is a Gram - negative stain?

Back 23

• Reddish/pink color
• Escherchia coli, Salmonella
• Decolorizes easily
• Gram - bacteria has a thin layer of Peptidoglycan surrounded by an outer layer of lipoproteins, phospholipids, and lipopolysaccharides.
• Tend to be more resistant to antibiotics.
• Alcohol dissolves the outer membrane, removes lipid plugs in the peptidoglycan, allows the crystal violet to escape, becomes colorless, takes up the counter stain safranin.

Front 24

What are the 4 reagents in a Gram Stain?

Back 24

1. Primary Stain= Crystal Violet
2. Mordant= Grahm's Iodine
3. Decolorizer= Ethanol/Ethanol Acetone
4. Counter Stain= Safranin

Front 25

What is the main component in the Bacteria Wall?

Back 25

Peptidoglycan

Front 26

What is the purpose of Mordant?

Back 26

To make the stain look better (primer) and to stick to the slide.

Front 27

What is Acid-fast staining?

Back 27

• Differential Stain
• Stained waxy cell wall is NOT decolorized by acid-alcohol
• Gram+ Mycobacterium leprae
• Mycobacterium tuberculosis
• Norcadia (genus stain on its own)
• Red/pink Color stain

Front 28

What is the cell wall of an Acid-fast stain bacteria made up of?

Back 28

An impermeable, wax-like lipid called

Mycolic Acid

Front 29

What is the shape of a bacillus bacteria?

Back 29

Bacillus = Rod shape

Front 30

What is the shape of the coccus bacteria?

Back 30

Coccus = Spherical/round

Front 31

What is the shape of staph bacteria?

Back 31

Staph = Clusters

Front 32

What is the shape of the strep bacteria?

Back 32

Strep= chain

Front 33

What is the spiral bacteria shape?

Back 33

Spiral= Spirillum,Vibrio, Spirochete

Front 34

What are pairs shape bacteria?

Back 34

Pairs shape bacteria = Diplococci,Diplobacilli

Front 35

What is BSL 1?

Back 35

• Standard microbial practices
• No safety equipment required
• Open benchtop sink

Front 36

What is BSL 2?

Back 36

• BSL 1 plus
• Limited access
• Biohazard warning signs
• "Sharps" precautions
• Safety manual of waste-decontamination policies
• Lab coat; cloves, as needed
• BSL 1 plus autoclave

Front 37

What is BSL 3?

Back 37

• BSL 2 plus
• Controlled access
• Decontamination of clothing before laundering
• BSL 2 plus protective lab clothing; enter and leave lab through clothing changing and shower rooms
• BSL 2 plus self-closing, double-door access

Front 38

What is BSL 4?

Back 38

• BSL 3 plus
• Separate building
• BSL 3 plus full-body air-supplied, positive pressure personnel suit
• BSL 3 plus separate building and building and decontamination facility

Front 39

What BSL is the lab that we work in?

Back 39

BSL 2