Microbiology Chapter 3 - Tools Of The Laboratory

Front 1

what are the five basic techniques to manipulate, grow, examine, and characterize microorgs in the lab

Back 1

inoculation
incubation,
isolation
inspection
identification

Front 2

what is it called when you:
producing a culture
Introduce a tiny sample (the inoculums) into a container of nutrient medium (swab a surface)

Back 2

innoculation

Front 3

what is isolation?

Back 3

separating one species from another
Separating a single bacterial cell from other cells and providing it space on a nutrient surface will allow that cell to grow in to a mound of cells (a colony)

Front 4

what is it called when you
small droplet of culture or sample spread over surface of the medium with an inoculating loop
Uses a pattern that thins out the sample and separates the cells

Back 4

streak plate method

Front 5

what is it called when:
sample inoculated serially in to a series of liquid agar tues to dilute the number of cells in each successive tubes
Tubes are then poured in to sterile Petri dishes and allowed to solidify

Back 5

loop dilation or pour plate method

Front 6

what is it called when you have a small volume of liquid, diluted sample pipette on to surface of the medium and spread around evenly by a sterile spreading tool

Back 6

spread plate method

Front 7

how are the media used to provide nutrients in the lab classified?

Back 7

Physical state
Chemical composition
Functional type

Front 8

what are semisolid media used for?

Back 8

Used to determine motility and to localize reactions at a specific site (not as common)

Front 9

what are solid media used for?

Back 9

Useful for isolating and culturing bacteria and fungi
provides a firm surface on which cells can form discrete colonies

Front 10

define synthetic media

Back 10

Synthetic media- compositions are precisely chemically defined (very well defined)

Front 11

define complex (nonsythetic) media

Back 11

if even just one component is not chemically definable (so if he puts 2g Na, 1g Sucrose, and yeast extract, it’s still complex media

Front 12

what do you use a general purpose media (nutrient agar) for? Describe it.

Back 12

to grow as broad a spectrum of microbes as possible (excludes micro orgs that don’t like high nutrient concentrations – pathogens like high nutrients) usually nonsynthetic, mixture of nutrients to support variety of m.o.

Front 13

describe enriched media

Back 13

contain complex organic substances (for example blood, serum, growth factors) to support the growth of fastidious bacteria (adding complexes that hellp the organism grow. Examples: blood agar, Thayer-Martin medium (chocolate agar - (heat shattered red blood cells)

Front 14

describe selective media

Back 14

contains one or more agents that inhibit the growth of certain microbes but not others.

Front 15

describe differential media

Back 15

allow multiple types of microorganisms to grow but display visible differences among those microorganisms.
(i.e. ecoli turns emerald green on a particular media while everything else turns pink.)

Front 16

you have an organism that can tolerate high levels of chlorine, what media would you use, selective or differential?

Back 16

selective

Front 17

you have an org that turns bright blue when grown , would you use selective or differential media?

Back 17

differential

Front 18

describe incubation

Back 18

an inoculated sample is placed in an incubator to encourage growth.
Usually in laboratories, between 20° and 40°C. (people are usually 25 – 30 deg. C)
Can control atmospheric gases as well.

Front 19

what is a pure culture (axenic)?

Back 19

Pure culture- growth of only a single known species (also called axenic)
Usually created by subculture

Front 20

what is a mixed culture?

Back 20

Mixed culture- holds two or more identified species

Front 21

what is a contaminated culture?

Back 21

Contaminated culture- includes unwanted microorganisms of uncertain identity, or contaminants. (This one will ruin your afternoon in a research lab).

Front 22

describe inspection and identification

Back 22

Inspection and identification: Using appearance as well as metabolism (biochemical tests) and sometimes genetic analysis or immunologic testing to identify the organisms in a culture.

Front 23

what are the Two key characteristics of microscopes:

Back 23

magnification and resolving power

Front 24

describe magnification

Back 24

Results when visible light waves pass through a curved lens
The light experiences refraction
An image is formed by the refracted light when an object is placed a certain distance from the lens and is illuminated with light
The image is enlarged to a particular degree- the power of magnification

Front 25

describe the two phases of magnification

Back 25

Objective lens- forms the real image
Ocular lens- forms the virtual image
Total power of magnification- the product of the power of the objective and the power of the ocular
(increase in magnification increases the size of the object)

Front 26

define resolution, what is it also known as?

Back 26

Resolution- the ability to distinguish two adjacent objects or points from one another (separate from magnification – high resolution increase distinction between two objects or points)
AKA resolving power

Front 27

shorter wavelengths provide a better or worse resolution?

Back 27

better

Front 28

why does oil immersion increase the numerical aperture?

Back 28

b/c it has a refractive ability to get more light in.

Front 29

increase magnification __________ the resolution

Back 29

decreases

Front 30

adjusting the iris diaphragm or using special dyes does what?

Back 30

help increase resolution at higher magnifications(adding contrast helps increase distinction)

Front 31

what are the four types of visible light microscopes?

Back 31

bright-field(what we use), dark-field, phase-contrast and interference

Front 32

what kind of microscopy is good for live, unstained and preserved, and stained specimens

Back 32

bright-field microscopy

Front 33

what kind of microscopy is good for visualizing living cells that would be distorted by drying or heat or that can’t be stained with usual methods

Back 33

dark-field microscopy

Front 34

what kind of microscopy is good for viewing intracellular structures such as bacterial spores, granules, and organelles in live, unstained cells

Back 34

phase-contrast microscopy

Front 35

what kind of microscopy is good for detailed view of live, unstained specimens, when you need color and three-dimensions

Back 35

interference microscopy

Front 36

what kind of microscopy is good for diagnosing infections caused by specific bacteria, protozoans, and viruses and for counting number of cells,

Back 36

fluorescence Microscopy

Front 37

what kind of microscopy is good for scanning various depths of a specimen at very high magnification?

Back 37

confocal microscopy

Front 38

what type of microscopy allows scientists to view the finest intercellular structures of cells at 5000x to 1,000,000x

Back 38

electron microscopy

Front 39

what are the two types of electron microscopy?

Back 39

transmission electron microscope (TEM) and
scanning electron microscope (SEM)

Front 40

what are TEMs good for

Back 40

looking at internal structures of cells and viruses

Front 41

what are SEMs good for?

Back 41

looking at surface structures

Front 42

what is positive staining?
what is negative staining

Back 42

Positive staining: the dye sticks to the specimen to give it color
The dye does not stick to the specimen, instead settles around its boundaries, creating a silhouette.

Front 43

simple stains

Back 43

Require only a single dye

All cells appear the same color but can reveal shape, size, and arrangement

Front 44

differential stains

Back 44

Use two differently colored dyes, the primary dye and the counterstain
Distinguishes between cell types or parts

Front 45

give three examples of differential stains

Back 45

Examples include Gram, acid-fast, and endospore stains

Front 46

describe gram staining

Back 46

The most universal diagnostic staining technique for bacteria
Differentiation of microbes as gram positive(purple) or gram negative (red)

Front 47

describe acid-fast staining

Back 47

Important diagnostic stain
Differentiates acid-fast bacteria (pink) from non-acid-fast bacteria (blue)
Important in medical microbiology

Front 48

describe endospore staining

Back 48

Dye is forced by heat into resistant bodies called spores or endospores
Distinguishes between the stores and the cells they come from (the vegetative cells)
Significant in medical microbiology
Most difficult