MicroLab Quizzes Flashcards
What happens to the light as you move to more powerful objectives?
Gets dimmer
What does it mean if objectives are parfocal?
Partially focused
What happens to field of view as you move to more powerful objectives?
Gets smaller
What is the only thing you should use to clean the ocular or objective lenses?
Lens paper
Objective band color when the objective is on scan?
Red
When the objective color band is yellow what is the objective on?
Low power
Objective band color when the objective is on high power?
Blue
Objective band color when the objective is on oil immersion?
White
What is the ocular magnification when the objective is on low power?
10x
What is the ocular magnification when the objective is on oil immersion?
10x
What is the objective magnification when the objective is on scan?
4x
What is the objective magnification when the objective is on low power?
10x
Which objective is at 400x total magnification?
High power
What happens when the objectives you see move to more powerful objectives?
Gets larger
Which objective is at 1000x total magnification?
Oil immersion
What is used to clean the microscope lenses?
lens paper
If you saw something a furry colony, what type of organism is it?
mold
True or False: normally petris dishes are placed in the incubator upside down.
true
Where are petri dishes suppose to be labeled?
on the bottom where the agar is
true or false: normal hand washing removes the bacteria from your skin, so nothing grew on the petri dish
false
What temperature is the incubator set as in degrees Celcius?
37*
How much inoculum (bacteria) do you use when making a smear from a broth culture?
6-8 loopfuls
How much inoculum (bacteria) do you use when getting it from a slant?
pinpoint
List 2 reasons why you fix a smear.
- to keep the bacteria & stain in place
- Shrink the cell
- kill bacteria
List an example of a basic stain
methylene blue
What kind of bond forms between the basic stain and the bacteria?
ionic bond
Give an example of an acidic stain.
congo red
What does an acidic stain do?
stain the background
Give an example of a basic stain?
maneval stain
What does a basic stain do?
stain the cell
How did the capsule look after the capsule stain procedure?
clear/white
Why do you never heat fix a capsule stain?
it shrinks the cell
What did we use in the capsule stain procedure to make the bacteria stick to the slide?
sheep serum
List 2 bacteria we used for Gram staining, designate their Gram (+/-) and their final color
Escherichia coli: Gram (-): pink
Staphylococcus aureus: Gram (+): purple
What is the counter stain in the Gram stain procedure?
Safranin
What is the primary stain in the Gram stain procedure?
Crystal violet stain
What is the primary stain in the spore stain?
malachite green
What is the counter stain in the spore stain?
safranin
In the spore stain, the spore appears as
green ovals
What color are acid-fast bacteria after staining?
reddish-purple
What is the primary stain in the acid-fast stain?
carbol fuschin
What is the counter stain in teh acid-fast stain?
methylene blue
List a species of bacteria that would be spore-forming.
Bacillus subtilis,
List a disease cased by a spore-forming bacterium
botulism
List a species of bacteria that would be acid-fast.
Mycobacterium smegmatis
List a disease caused by an acid-fast bacterium
tuberculosis (TB)
What procedure could we perform that would separate mixture of different kinds of bacteria?
streak plate isolation
What does a colony start out as?
1 bacterium that divides multiple times and isolates itself from other bacteria
What are 2 problems with cultures when working with unknowns?
- contamination –>asceptic transfer
2. Over growth & denature
When you get your unknown, where will you keep your reserve stock?
fridge
What does a positive catalase test look like?
bubbles
What is the product that you are seeing when you have a positive catalase test?
O2
What is the substrate for catalase?
H2O2
The catalase test distinguides between 2 genera of Gram (+) bacteria. List them and then designate how they test for catalase.
Streptococcus –> catalase (-)
Staphylococcus –> catalase (+)