RP6: Aseptic Techniques

Question 1

Why would agar be boiled before used in a microbiology practical?

Answer 1

to kill unwanted bacteria

Question 2

Why would the same volume of culture be transferred to each agar plate?

Answer 2

to allow for comparison

Question 3

How would you achieve more accurate results when determining a specific concentration?

Answer 3

• smaller intervals between set of values
• repetitions of each

Question 4

Give 4 aseptic techniques…

Answer 4

• wipe down surfaces with disinfectant
• use a bunsen burner for upward air movement
• flame the bottle neck to prevent bacteria entering
• keep vessels closed as much as possible

Question 5

Why is the bacteria incubated at 25C?

Answer 5

to prevent the growth of harmful bacteria, which occurs at higher temperatures

Question 6

How can you compare the effectiveness of different antibiotics?

Answer 6

find the area of the zone of inhibition

Question 7

Why should the lid not be completely taped on the petri dish?

Answer 7

allow oxygen to enter and prevent
harmful anaerobic bacteria

Question 8

What graph could be drawn from the results of this investigation?

Answer 8

bar graph showing the area of the zone of inhibition against type of antibiotic