Immunity

Question 1

why are aseptic techniques used?

Answer 1

to prevent contamination when working with microorganisms for both the microbe culture and the individual working with the microbes.

Question 2

what is used to culture microorganisms

Answer 2

-solid agar or//
-liquid broth

Question 3

what is the procedure for transferring microorganisms?

Answer 3

-flame metal inoculating loop in the hottest part of the Bunsen burner until it becomes red-hot.
-air cool the loop to not kill any microorganisms.
-open lid of culture bottle with the same hand and don’t allow it to touch the bench.
-pass neck of culture bottle quickly over Bunsen flame (repeated before replacing lid on culture bottle).
-lid of petri dish should only be open slightly when adding microorganisms.

Question 4

how should the petri dish be incubated?

Answer 4

-upside down.
-at an appropriate temperature.

Question 5

what are e-strips?

Answer 5

prepared strips that contain a concentration gradient of antibiotic running the length of the strip.

Question 6

what is the procedure to prepare a streak plate to isolate single colonies?

Answer 6

-use an inoculating loop to spread the microorganisms over a small section of the agar in the petri dish.
-with a new / sterilised loop, streak several lines of microorganism across the agar at an angle.
-repeat second stage one or twice, using a sterile loop each time.
-make a final single streak.
-incubate petri dish at a suitable temp.

Question 7

what is the procedure for investigating the antimicrobial properties of plants?

Answer 7

-Grind up leaves in ethanol with a mortar and pestal.
-prepare sterile agar plates.
-spread fungus or bacteria on the plates.
-soak a small disk of sterile filter paper with each plant extract and place in the petri dish.
-incubate for 24-48 hours and compare results.