Ch 2: Studying Microbes Flashcards Preview

BIO 246: Microbiology of Human Disease > Ch 2: Studying Microbes > Flashcards

Flashcards in Ch 2: Studying Microbes Deck (19):
1

What are the 5 "I's" of the Microbiology lab?

1. Inoculation - specimen placed in artificial growth environtment
2. Incubation - growth
3. Isolation - separate species of interest
4. Inspection - Observe results
5. Identification - determine species identity

2

What is inoculation?

Creating a culture from a specimen
-flame sterilize inoculating loop (aseptic)
-Collect specimen, transfer to agar dish
-also can transfer to broth tube

3

What is incubation?

For each microbe, culture, requires time and temp

4

What is a culture medium?

Artificial growth environment
-Liquid media (broth) or solid media (agar)

5

What is a selective medium?

contains growth inhibitor that inhibits growth of many bacteria

6

What is a differential medium?

contains biochemical indicator that changes color to show an acid is produced during fermentation of a sugar

7

What is isolation?

A dilution technique used to separate microscopic cells
-grow macroscopic colonies (pure cultures)

8

What are the different methods of isolation?

Loop dilution and Streak Plate

9

What is inspection (part of the 5 I's)?

Looking at:
1) Microscopic appearance
2) Cellular metabolism and function
3) Genetic and Immunological characteristics

10

Which of the 5 I's uses the loop-dilution technique?

Isolation

11

What are the components of a selective broth medium for the growth of staphylococci?

1. Protein rich nutrient extract
2. Salt
3. Water

12

What is resolution?

measurement of the clarity of the image produced
-dependent on wavelength of light source

13

WHat is light microscopy?

Uses Glass lens that causes light refraction resulting in magnification

14

What are the parts of the light microscope?

Ocular Lens = what you look through
Objective lens = the different magnifications
Condenser lens = focuses light
Light source = bulb

15

How do you create contrast in cell structures?

Differential staining
-Gram Stain
-Acid-fast stain
-Spore Stain

16

Besides staining, how can contrast be achieved?

VISIBLE LIGHT
1) Bright-field
2) Dark-field
3) Phase-contrast

UV LIGHT
1) Fluorescent microscopy
2) Confocal microscopy

17

Which part of the microscope magnifies the image of the specimen?

Objective lens and Ocular lens

18

If you wanted to visualize a cross-section of a 20 nm virus particle, what type of microscopy would be used?

Transmission Electron Microscope (TEM)

19

What microscopes give you the highest magnification?

ELECTRON MICROSCOPES
1) Transmission Electron Microscope (TEM)
-produces cross sectional image

2) Scanning Electron Microscope (SEM)
-produces surface scan of specimen