Infection and response practical Flashcards
Agar jelly
Contains all nutrients needed for growth of bacteria.
A danger of growing bacterias
There is a risk of mutation in the DNA causing that the bacteria become harmful.
Agar gel plate
Petri plate and agar gel
How to avoid contamination?
- sterilise all Patri dishes and agar gel
- sterilise inoculating loop by Bunsen burner flame
Inoculating loop
Used to transfer the bacteria into the agar gel.
Adhesive tape
Used to attach the lid of the Petri dish, which prevents the lif from falling off and unwanted microorganisms entering.
Place the agar plate upside…
down into incubator. This stops moisture from dropping down onto bacteria and disturbing the colonies.
A temperature in the incubator must be…
25 degrees to reduce the risk that harmful bacteria will grow.
- Clean the bench with…
disinfectant solution.
- Sterilises an inoculating loop by…
Bunsen burner flame.
- Open a sterilise agal gel plate…
near a Bunsen burner flame. This kills the bacteria in the air.
- Use the loop to spread…
the chosen bacteria evenly in the plate.
- Place sterile filter paper discs contining…
antibiotics onto the plate.
- Incubate the plate at…
25 degrees and leave it for 48 hours.
Zone of inhabitation
Around the discs, we have a region where the bacteria have not grown. It can be calculated by π r2
