Sterilisation Techniques

Question 1

How to minimise risk of contamination

Answer 1

Wipe all surfaces with 10% bleach solution solution

All equipment is placed in a bucket that will be sterilisied with a 10% bleach solution overnight

Question 2

How to prepare work area

Answer 2

Remove all objects other than those required

Question 3

Prepare test tubes

Answer 3

Move them through the blue flame of a bunsen burner

Question 4

How to open a petri dish

Answer 4

Lift at an angle no greater than 45*C
Do no cough/breathe into the open dish, work as quickly as possible

Question 5

Inoculating loop

Answer 5

Use this to spread the sample onto the nutrient agar. Sterilise loop by moving it slowly through the blue flame of the Bunsen burner

Question 6

How to spread sample

Answer 6

Use a zig-zag motion, do not dig into the surface.

Question 7

How to store the dish

Answer 7

Seal around the edge with sticky tape, lable the underside (so lid cannot be lost)

Place it upside down in the incubator for required dats to prevent condensation from forming on the agar surface.

Question 8

Risk assessment E. coli

Answer 8

Hazard:

• E. coli is classified as a Risk group 1 bacteria, meaning that it poses low individual and community risk

Risk:

• However, E. coli can still be pathogenic for immuno-compromised individuals, so physical containment procedures should be applied when working with E. coli

Management:

• PPE should be worn at all times within the laboratory when working with E. coli. PPE should protect the front part of the body. For example, long-sleeved lab coats, nitrile gloves, and safety glasses should be worn
• Food or drink should not be brought into the laboratory
• Long hair should be tied back, to avoid contaminating the bacterial plates