For Quiz 2

Question 1

negative stain (white part)

Answer 1

big thick layer of polysaccharides, around bacteria.

Question 2

gram staining

Answer 2

used to identify 2 diff envelope morphologies found in bacteria.

Question 3

cells are pigmentless, so for gram staining

Answer 3

use brightfield

Question 4

Gram negative (pink)

Answer 4

CV-I can get out bc thin layer.
chain of glucose is hypotonic.
peptide stem: covalently bonded, cross linked

Question 5

gram positive (purple)

Answer 5

CV-I will stay in bc thick layer, cant get through.

Question 6

best way to test an unknown bacterium by staining is to use

Answer 6

control strains.

known gram + … unknown… known gram neg

Question 7

kinyoun acid fast stain

Answer 7

retained if bacterium has waxy substance in cell wall such as mycolic acid.
retains carbolfuchsin, even if acid alcohol decolorizer is used

Question 8

Methylene blue counterstain

Answer 8

used to see other cells

Question 9

cells prior to staining
after staining with carbolfuchsin,
brilliant green is used to

Answer 9

transparent.
cells become reddish purple
counterstain acid fast neg cells.

Question 10

mycobacteria contain mycolic acids in their cell envelope

Answer 10

• create waxy coating
• prevents phagocytosis by macrophages
• excludes many antibiotics

Question 11

microbacterial disease

Answer 11

leprosy. grow at cooler temp. also microbacterium tuberculosis

Question 12

endospore stain

Answer 12

to see Bacillus and Clostridium

• malachite green
• heat soffens endospores

Question 13

difference bw
bacillus
and clostridium

Answer 13

• aerobic or anaerobic bacteria. in soil and water.

- dies in air, cant protect itself against O.

Question 14

steps in staining

Answer 14

CV-1 min 
H20 wash 
I-1 min 
H20 wash 
add drop wise decolorizer. (45 degree angle) 
H20 wash 
flood with Safranin 
h20 then bibulous paper