Aseptic Technique: RP

Question 1

What is aseptic technique?

Answer 1

• Working in sterile conditions to prevent contamination of sample and infection of others.

Question 2

Before inoculation, what sort of steps should we do to prevent contamination of our bacteria sample?

Answer 2

• Sterilise al equipment to kill microbes.
• Sterilise work surfaces with disinfecant to kill microbes.
• Wash hands with soap to kill microbes.

Question 3

During inoculation, what sort of steps should we do to prevent contamination of our bacteria sample?

Answer 3

• Work near bunsen burner, convection currents will sterilise the air.
• Only open petri dish SLIGHTLY/ at angle.

Question 4

After inoculation, what sort of steps should we do to prevent contamination of our bacteria sample?

Answer 4

• Sterilise all equipment to kill microbes (ie. place in disinfectant.)
• Sterilise work surfaces with disinfectant to kill microbes.
• Wash hands with soap to remove microbes.

Question 5

What do we pass through bunsen burner roaring flame whilst preparing lawn plate culture of bacteria?

Answer 5

• Neck of the bottle (that had bacteria in it.)
• After you have transferred certain volume of bacteria using a sterile pipette, flame the neck of bottle again!

Question 6

What is a petri dish with bacteria culture in known as?

Answer 6

• Known as a lawn plate.

Question 8

Why do we leave our lawn plate for 5-10 minutes after spreading bacteria evenly across the agar?

Answer 8

• Allows for broth to be absorbed into the agar.

Question 9

Why do you GENTLY use forceps to press down the antibiotic multi-test ring onto the lawn plate? Where do you press down?

Answer 9

• Press down on parts between different antibiotics, not on the antibitoics directly as this will lead antibiotic to be released instantly!!

Question 10

Why do we only slightly tape the agar plate down? ie. not all the way.

Answer 10

• Prevents growth of harmfu, anaerobic bacteria.
• Bacteria need the oxygen to replicate.

Question 11

What do we meaure after we have incubated the agar plate for 72 hours with antibiotic multi-use ring?

Answer 11

• Measure diamaters of zones of inhibition.

Question 12

What graph do we plot for this RP?

Answer 12

• Bar chart

Question 13

How would we conclude that a certain antibiotic is SIGNIFICANTLY more effective than other antibiotics from this practical?

Answer 13

• Mean diameter of zone of inhibition is largest AND it’s standard deviation doesn’t overlap.

Question 14

Areas of innacuracy from this practical?

Answer 14

• Only tested on 1 bacteria.
• Only tested 8 antibiotics.
• Don’t know of any side-effects anitbiotic may have on humans.

Question 15

What do we use to spread the bacteria culture in this RP?

Answer 15

• Plastic, sterile spreader.