Micro Lab Test 1

Front 1

how does a negative stain differ from other stains?

Back 1

The dye is acidic and has a negative charge

Front 2

What is a benefit of using a negative stain?

Back 2

You don't have to heat fix (good for fragile organisms/cells). Also, it produces minimal cell shrinkage.

Front 3

What is the theory behind using an acidic stain?

Back 3

The negative charge repels the stain, so the cell remains uncolored against a colored background.

Front 4

What are two common acidic stains

Back 4

nigrosin and eosin

Front 5

What is an autoclave bag?

Back 5

It is used for decontamination. The items from the bag are put into an autoclave to sterilze them at 121 degrees

Front 6

needles and glass should be put in

Back 6

sharps container

Front 7

bright field microscopy is the

Back 7

most commonly used

Front 8

the best limit of resolution is

Back 8

.2 micrometers

Front 9

total magnification is

Back 9

mag of objective x mag of ocular

Front 10

eyeball to base of microscope

Back 10

ocular lens, objective lens, specimin, condensor, light

Front 11

Actual limit of resolution
D=

Back 11

wavelength /
NA condensor + NA objective

Front 12

Numeric Aperture is the

Back 12

measure of a len's ability to capture light coming from the specimin and use it to make an image

Front 13

stage micrometer

Back 13

used to calibrate microscope
(no numbers on it)

Front 14

ocular micrometer

Back 14

is a scale with uniform incrmenets of unknown size. It has to be callibrated with the objective

Front 15

diplo
strepto
tetrad
sarcina
staphylo

Back 15

two cocci
chain cocci
four cocci
eight cocci
grape like structure

Front 16

bacillus

Back 16

rod

Front 17

coccobacillus

Back 17

short rod that could be confused with cocci

Front 18

vibrio

Back 18

curved rod

Front 19

pleomorphic

Back 19

grows in a variety of shapes

Front 20

basic steps in making a bacterial smear

Back 20

drop water, add bacteria w innoc. loop, spread, air dry (flame loop again), pass through flame

Front 21

2 benefits of making bacterial heat fixed smear?

Back 21

it makes the bacteria adhere to the slide and it coagulates the protein to make them more visible

Front 22

drawbacks to heat fixing a smear?

Back 22

it distorts the cells to an extent.

Front 23

theory behind basic stain

Back 23

basic stains are attracted to the negative charge on the surface of most bacterial cells. Thuis the cell becomes colored

Front 24

3 common basic stains

Back 24

methylene blue, safranin, crystal violet

Front 25

how is negative stain different from other stains?

Back 25

The dye is acidic and has a negative charge

Front 26

examples of differential stains?

Back 26

gram, acid fast, capsule, spores or flagella

Front 27

differential stains are also referred to as

Back 27

structural stains

Front 28

what is the Ziehl-Neelsen (ZN) method and sequence of steps

Back 28

Acid fast stain.
heat fix emulsion, cover smear w paper towel and carbolfucshin stain, steam for 5 min, remove paper, rinse, decolorize w acid alcohol, rinse w distilled water, counterstian w M. blue 1 min., blot dry

Front 29

function of the methylene blue in acid fast?

Back 29

It stains the acid fast negative cells

Front 30

2 diseases caused by mycobacteria?

Back 30

leprosy and tuberculosis

Front 31

function of capsule stain

Back 31

detects cells capable of producing an extracellular capsule.

Front 32

capsule production

Back 32

increases virulence in some microbes, making them less vulnerable to phagocytosis

Front 33

capsule technique

Back 33

stains around cells. The capsule remains unstained and appears as a white halo against a colored background.

Front 34

capsules are composed of

Back 34

polypeptides which are difficult to stain

Front 35

what is an endospore

Back 35

a dormant form of bacterium thatb allows it to survive lean environmental conditions

Front 36

Endospore stain process

Back 36

heat fixed smear, cover w paper. apply malachite green steam 5 minutes, counterstain w safranin 1 min, rinse, blot dry

Front 37

endoposre stain chemicals

Back 37

malachite green and safranin

Front 38

2 genera of bacteria w endospores

Back 38

bacillus and clostridium

Front 39

would bacteria be likely pathogenic at 25 degrees?

Back 39

Probably not psychrotrophs, usually are not pathogenic

Front 40

would bacteria be likely pathogenic at 37 degrees?

Back 40

mesophiles,

Front 41

free living

Back 41

microbe does not reside on plant or animal host and are not pathogenic.

Front 42

opportunistic pathogen

Back 42

capable to cause disease

Front 43

reservoir

Back 43

area including sites outside the host where microbe resides and serves as a poential source of infection

Front 44

pathogens

Back 44

associated w host

Front 45

shape

Back 45

circular, irregular, punctiform (tiny, pinpoint)

Front 46

margin

Back 46

entire (smooth, no irregularites), undulate (wavy), lobate (lobed), filamentous, or rhizoid (branched like roots)

Front 47

elevations

Back 47

flat, raised, convex, pulvinate (very convex), and umbonate (raised in center)

Front 48

texture

Back 48

mucoid, moist or dry

Front 49

pigment description

Back 49

color, opaque, translucent, shiny or dull