Bacteria Isolation

The use of sterile techniques and agar media enabled early microbiologists to:

• Study pure cultures

• Demonstrate the nature of infectious disease

• Study mixed cultures

• Study agar-metabolizing cultures e

What are the requirements for isolation?

• Culture medium

• Petri dish (agar plate)

• Separation tools

• All of the above

What is the first step in the streak plate method of isolation technique

• Flame loop in between each quadrant that you make (cool before streaking)

• Use the thin edge of the loop to give better isolation than the flat part

• Hold the plate in the opposite hand while streaking (do not lay flat on the lab benchtop)

• Keep plates closed between streaking (don't talk, cough on plates, etc)

What is the third step in the streak plate method of isolation technique

• Flame loop in between each quadrant that you make (cool before streaking)

• Use the thin edge of the loop to give better isolation than the flat part

• Hold the plate in the opposite hand while streaking (do not lay flat on the lab benchtop)

• Keep plates closed between streaking (don't talk, cough on plates, etc)

In what quadrant do the isolated colonies appear in the streak plate method of isolation?

• 1st quadrant

• 2nd quadrant

• 4th quadrant

• All quadrant

A culture medium consisting of agar, human blood, and beef heart is a _____ medium.

• Complex

• Selective

• Differential

• Chemically defined

After using an inoculating loop or needle to transfer a culture from one medium to the next, what stop should be taken next to avoid contamination.

• Heat the inoculating loop or needle with the bunsen burner flame until it becomes cool to the touch.
• Heat the inoculating loop or needle with the bunsen burner flame until it becomes purple hot.
• Heat the inoculating loop or needle with the bunsen burner flame until it becomes red hot.

Which of the following should be done first in the event a liquid broth culture is spilled?

• Cover the spill with paper towels to prevent the microorganisms from being spread around.
• Do nothing, germs are for babies.
• Lick it, yum, takes good.