問題一覧
1
What are the magnifications and total magnifications of the lenses ?
scanning: 4x-40x, low dry: 10x-100x, high dry: 40x-400x, oil immersion: 100x-1000x
2
What is resolution ?
ability to see 2 objects separate
3
Define parfocal
doesn’t need any course adjustment and should automatically be focused after high dry
4
What is the function of the diaphragm ?
controls the amount of light which reaches the slide by opening or closing it
5
What is the function of the condenser ?
collect and direct the light from the light source to the slide being studied
6
What is the field of view ?
the area you can see through the microscope lenses
7
When you first focus on an object, you start with _____ focus then you adjust with _____ focus
course, fine
8
What is the first thing to be done when entering the lab ?
clean table and wash your hands
9
Why must you clean the table top before and after the lab time ?
to prevent cross contamination of all material
10
List two reasons to heat fix a bacterial slide
bacteria sticks to the slide , kills bacteria
11
Why do most biological stains have a positive charge (basic) ?
gram (+): teichoic acid, gram (-): lipopolysaccaride
12
Why does negative stain give a more accurate measure of cell size ?
we don’t hear fix and we don’t distort the cell
13
What is the purpose of simple stain ?
tells you Shape and arrangement of bacteria
14
What is the difference between simple and differential staining ?
simple shows only shape and differential shows shape and distinguishes between two different species
15
Which stain has methylene blue and is heat fixed ?
simple
16
Which stain has crystal violet as it’s primary, gram’s iodine as the mordant, ethyl alcohol as the decolorizer, safranin as the counter stain and its heat fixed ?
gram stain
17
Which stain has carbon fuchsin as primary, heat as the mordant, acid alcohol as the decolorizer, methylene blue as counter stain, and its heat fixed ?
acid fast
18
Which stain has malachite green as primary, heat as the mordant, no decolorizer, safranin as the counter stain, and its heat fixed ?
endospore
19
Which stain has acid fusion as the primary, no mordant or decolorizer, Congo red as the counter stain, and it’s not heat fixed ?
negative capsule
20
What does a mordant do ?
forms a stable complex with crystal violet allowing the stain to adhere to the G+ cell wall and G- cell outer membrane
21
List a stain that it negatively charged (acidic)?
Congo red, nigrosin
22
What color are gram + cells
blue-purple
23
What is an example of gram + cell ?
staphylococcus aureus
24
What color are gram - cells ?
red-pink
25
What is an example of gram - cells ?
E.coli, serratia
26
What are the differences in gram + and gram - ?
cell wall
27
What genus of bacteria are acid fast ?
mycobacterium
28
Why are they acid fast ?
cell wall contains a high amount of mycolic acid
29
What color are acid fast cells ?
red-pink
30
What color are non-acid fast cells ?
blue
31
What 2 genera are endospore formers ?
bacillus and clostridium
32
After endospore staining what color are the spores ?
green
33
What color are the vegetative cells ?
red-pink
34
After negative staining what color is the capsule ?
colorless
35
What color are vegetative cells ?
red-pink
36
What color is the background ?
blue