Microscope: parts and uses
Staining
Terms
Tests
Identifying Unknowns
100
Name this part of the microscope. [slide 1]
What is the objective lens
100
a. This Gram reaction is associated with a pink color. b. This Gram reaction is associated with a purple color.
What is a. Gram negative b. Gram positive
100
This type of bacteria colonizes our body without causing any harm.
What is normal flora.
100
When performing a catalase test, a positive reaction can be determined how.
production of gas bubbles
100
This is the first step to identifying an unknown organism
What is a gram stain (and looking at colony morphology on media plate)
200
This part of the microscope will provide a certain type of contrast that will help you observe colorless organisms. [slide 2]
What is the phase ring
200
Identify the Gram reaction and morphology of this bacteria. [slide 4]
What is Gram negative rods/bacilli
200
This term describes the relationship between two or more organisms where one organisms is harmed while the other benefits. a. mutualism b. commensalism. c. parasitism
What is parasitism. All of these are subcategories of symbiosis
200
What are the three hemolytic patterns that can be seen when using Sheep's blood agar [slide 5]
alpha hemolytic Beta gamma
200
Look at this gram stain. What is the Genus species? [slide 8]
Trick question. You can't tell from just a gram stain. Need more testing to be sure!
300
This objective lens has the highest magnification and requires ______ in order to use.
What is the oil immersion lens OR 100X objective; oil
300
Define the morphology of this bacteria (shape and arrangement) [slide 3]
What is Gram positive cocci in chains
300
The term defines the clearing of bacteria that occurs around an antibiotic disc in a Kirby Bauer test. What does it mean when you see this clearing?
What is the zone of inhibition. The clearing means the bacteria is susceptible to the antibiotic....you would want this antibiotic if you were infected with the same bacteria!
300
Name three ways to determine if a microorganism is motile
1. Wet Mount 2. Motility test (semisolid media such as the SIM tube) 3. Flagellar stain
300
Is this Enterotube inoculated? How do you know? [slide 7]
No. No color changes from the negative tube in the key
400
I want to look at a Gram stain result. This is the type of microscopy I will use.
What is brightfield microscopy
400
The Gram stain is a. simple stain b. differential stain c. structural stain
Differential stain
400
These are inanimate objects that can spread disease.
What are fomites
400
Identify the tube corresponding to an aerobic culture [slide 6]
A
400
When would you perform a susceptibility test?
When trying to confirm Streptococcus pyogenes or Streptococcus pneumoniae
500
When I want to view a living microorganism to see its motility and its true size/shape, I should set up a __________ and use this type of microscopy
(wet mount) What is phase microscopy?
500
If you don't add the mordant during the Gram staining process, what color would you expect the culture to be.
pink! The purpose of the mordant is to trap the crystal violet dye in the peptidoglycan layer of Gram + cells. If it doesn't get trapped, the ethanol will wash it away just like it does in Gram - cells. It will then take up the safranin in the final staining step and appear pink under the microscope.
500
This type of bacteria grows optimally in cold conditions a. psychrophile b. mesophile c. thermophile
psychrophile
500
If you only need Gram + bacteria to grow, what type of media would you use. Name an example.
What is selective media. CNA only allows Gram + organisms to grow. EMB only allows Gram - growth. MSA allows only what to grow?
500
You know your bacterial culture is either Staph. epi or Staph aureus. What test can you perform to determine which species you have?
Coagulase test....using rabbit plasma or using MSA plate.
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