Methods in Microbiology Flashcards
1
Q
Describe Aseptic Technique
A
- nothing contaminates your work, you or your surroundings
2
Q
Define Subculturing
A
- transferring microorganisms from 1 culture to another in pure form
3
Q
How can initial cultures & subcultures be performed ?
A
- streak plates
- spread plates
4
Q
What are spread plates used?
A
- counting microorganism in a liquid sample
- sampling an environmental surface
5
Q
Describe a Lawn Culture
A
- provides a uniform surface growth of the bacterium
- used for antibiotic sensitivity testing & preparing bacterial antigens/vaccines
6
Q
How are lawn cultures prepared?
A
- by flooding the surface of the plate with a liquid suspension of the bacterium
7
Q
How would you describe a culture ?
A
- amount of growth
- colony morphology
8
Q
What categories are involved in colony morphology ?
A
- shape
- margin
- elevation
- size
- texture
- appearance
9
Q
What are the various shapes that cultures can display ?
A
- circular
- rhizoid
- irregular
- filamentous
- spindle
10
Q
What are the various margins a colony can display?
A
- entire
- undulate
- lobate
- curled
- filamentous
11
Q
What are the various elevations a colony can display ?
A
- flat
- raised
- convex
- pulvinate
12
Q
What are the different sizes a colony can demonstrate ?
A
- punctiform
- small
- moderate
- large
13
Q
How to prepare a bacterial smear ?
A
- ensure slide is clean
- label with pencil
- place loopful of water on slide & mix with colony
- allow smear to dry fully
- heat fix cells via passing through flame of bunsen
14
Q
Describe the process of Gram Staining
A
- flood slide with crystal violet = 1 min
- rinse then flood with iodine = 1 min
- rinse then flood with alcohol/acetone = 20s
- flood with safranin = 1 min
15
Q
What colour are gram negative bacteria after staining?
A
pink
