Midterm: Isolation Technique

Question 1

What is the purpose of an isolation procedure?

Answer 1

To reduce the concentration of microbes by mechanically separating them using a semisolid agar

Question 2

How many loop-fulls of bacteria are transferred r the Petri dish?

Answer 2

1

Question 3

What is done to the inoculation loop after the initial load of bacteria is applied

Answer 3

It is sterilized

Question 4

What is a CFU?

Answer 4

Colony forming unit

Question 5

Why do microbiologists want samples form isolated colonies, rather than undifferentiated masses?

Answer 5

Mixed or contaminated cultures will give inaccurate as/or inconsistent results and cannot be reliably tested.

Question 6

Why are isolation techniques needed when studying microbial specimens taken from patients in a medical setting or from environmental samples?

Answer 6

In a clinical setting there are lots of microbes and isolating the microbes allows for one to differentiate

Question 7

How can isolation techniques be used to salvage a contaminated culture?

Answer 7

You can take the desired culture and isolate it and then isolate it again until it is no longer contaminated

Question 8

What problems might arise when attempting to salvage a contaminated culture?

Answer 8

If a contaminated culture is left too long the contaminated may kill off the original species

Question 9

What are the two common isolation techniques used in the microbiology lab?

Answer 9

The spread plate technique and the streak plate technique

Question 10

Which isolation technique often involves diluted cultures?

Answer 10

The spread plate technique

Question 11

Which isolation technique does not involve diluted cultures?

Answer 11

The streak plate technique