4.12

Question 1

What is an additional precaution against contamination

Answer 1

Leave a lighted Bunsen burner on the bench

Question 2

Step 1

Answer 2

Sterilise the inoculating loop by holding it in the Bunsen burner until it glows red hot and then leave it to cool,

Question 3

Step 2

Answer 3

Dip the sterilised loop in the suspension of the bacteria. Streak the loop across the surface of the agar. Replace the petri dish lid, close the tape and turn the dish up[side down.