Microscopy/staining/classification

Question 1

What is resolution?

Answer 1

the shortest distance between two points on a specimen that can still be distinguished by the observer as separate entities

Question 2

What is contrast?

Answer 2

Differences in intensity between two objects, or between an object and background

Question 3

What is the importance of staining?

Answer 3

increases contrast and resolution by coloring

Question 4

Smear of microorganisms (thin film) made prior to staining, must be fixed with what?

Answer 4

heat

Question 5

What is a Gram stain? (colors)

Answer 5

purple or magenta/red

Question 6

What is an Acid-Fast stain? (colors)

Answer 6

blue (non acid-fast) or red (acid-fast)

Question 7

What is an Endospore stain? (colors)

Answer 7

green (endospores) or magenta (vegetative cells)

Question 8

What are mycobacteria?

Answer 8

Mycobacteria are a group of bacteria that do
not have the typical peptidoglycan cell walls
- referred to as Acid-Fast bacteria

Question 9

What is unique about mycobacteria cell walls?

Answer 9

Their cell walls have a high waxy mycolic acid content, making them resistant to decolorization by acids during staining procedures such as the Gram stain

Question 10

What are a series of paired statements where only one of two “either/or” choices applies to any particular organism?

Answer 10

Dichotomous keys